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The Canadian global change program
Adv. SpaceRes, Vol.
9, No. 7, pp. (7)23-(7)27, 1989 Printed in Great Britain. All rights reserved.
THE C A N A D I A N PROGRAM
0273-1177/89 $0.00 +.50 Copyright © 1989 COSPAR
GLOBAL CHANGE
J. Cihlar* and M. Dence** *Canada Centre for Remote Sensing, 2464 Sheffield Road, Ottawa, Ontario, K1A OY7, Canada **Royal Society of Canada, 344 Wellington Street, Suite 3006, Ottawa, Ontario, K1A ON4, Canada
ABSTRACT This p a p e r d e s c r i b e s the p r o p o s e d C a n a d i a n c o n t r i b u t i o n to the I n t e r n a t i o n a l G e o s p h e r e - B i o s p h e r e Program. While the C a n a d i a n p r o g r a m is at the p l a n n i n g stage, m a j o r themes for focussed effort have been identified in three domains: terrestrial - atmospheric interactions, marine - atmospheric interactions, and the A r c t i c r e g i o n as an ecosystem. The p a p e r further e l a b o r a t e s on the c o n t r i b u t i o n of s a t e l l i t e o b s e r v a t i o n s to this p r o g r a m by o u t l i n i n g g u i d i n g p r i n c i p l e s and p r o p o s e d remote sensing activities. INTRODUCTION The e n v i r o n m e n t at the Earth's surface appears to be u n d e r g o i n g c h a n g e s that may have h i g h l y s i g n i f i c a n t c o n s e q u e n c e s for the w e l l - b e i n g and p r o s p e r i t y of the h u m a n species. These changes are related to various key c o m p o n e n t s of the earth system including its atmosphere, oceans, and land ecosystems. E x a m p l e s of such changes are potential greenhouse warming caused by the increase in c a r b o n dioxide c o n c e n t r a t i o n in the a t m o s p h e r e as well as those of other r a d i a t i v e l y active gases including m e t h a n e and c h l o r o f l u o r o c a r b o n s ; d e f o r e s t a t i o n and desertification occurring in v a r i o u s parts of the world; and the c o n t i n u i n g d e t e r i o r a t i o n of soil productivity. Some of these are e x p e c t e d to lead to l o n g t e r m m o d i f i c a t i o n s of the e n v i r o n m e n t a l c o n d i t i o n s at or near the Earth's surface. For instance, model p r e d i c t i o n s have shown that the doubling of CO2 in the atmosphere could in central C a n a d a increase surface t e m p e r a t u r e during the summer months of up to 9 d e g r e e s C e l s i u s and reduce the available soil water by more than 50% (Manabe and Wetherald, 1986). The rise in sea level with resulting flooding of coastal cities around the world, modified patterns of the hydrological cycle, and g e o g r a p h i c a l shifts in vegetation distribution are examples of p o s s i b l e future e n v i r o n m e n t a l changes. As a h i g h - l a t i t u d e country, C a n a d a has c e r t a i n d i s t i n c t i v e e n v i r o n m e n t a l and c l i m a t i c features w h i c h are c a u s e d by the Sun - E a r t h geometry, the p l a n e t a r y m o t i o n of the Earth, and the regional g e o l o g i c a l history. The i n t e r r e l a t e d consequences of these factors include strong regional heat loss, thus r e q u i r i n g transport of heat from low latitudes; important t r a n s f e r p r o c e s s e s c o n c e r n e d w i t h r a d i a t i o n (albedo) and heat (phase changes) r e s u l t i n g from the p r e s e n c e of snow and ice; and s e n s i t i v e i n t e r a c t i o n s b e t w e e n o c e a n current ( e s p e c i a l l y in the A r c t i c Ocean), p o l a r and t e m p e r a t e air masses, and the regional climate. In addition, v a r i o u s C a n a d i a n e c o s y s t e m s are of special significance for global change. These include the cold water marine ecosystems, the boreal forest and wetlands, and the anthropogenically m o d i f i e d e c o s y s t e m s at lower l a t i t u d e s (a " 5 0 0 - y e a r record of change"). As s c i e n t i s t s a t t e m p t to more p r e c i s e l y define the d i r e c t i o n and m a g n i t u d e of the future e n v i r o n m e n t a l changes, it has become i n c r e a s i n g l y o b v i o u s that our u n d e r s t a n d i n g of the p r o c e s s e s o c c u r r i n g at and near the E a r t h ' s surface is inadequate. This realization in turn led to the f o r m u l a t i o n of v a r i o u s r e s e a r c h p r o g r a m s a i m e d at filling the gaps in the u n d e r s t a n d i n g of the E a r t h and of the c h a n g e s that occur in this system. Two p r o g r a m s are n o t a b l e for their scope, the I n t e r n a t i o n a l G e o s p h e r e - B i o s p h e r e Program: A S t u d y of G l o b a l C h a n g e and the U.S. E a r t h S y s t e m Science program. Both p r o g r a m s focus
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J. Cihlar and M. Dence
on global change. The objective of the International Geosphere - Biosphere Program (IGBP) is "to obtain scientific understanding of the Earth system by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to evolve in the future" (Committee on Space Research, 1987, p. 18). The goal of the Earth System Science program is "to describe and understand the interactive physical, chemical, and biological processes that regulate the Earth's unique environment for life, the changes that are occurring in this system, and the manner in which they are influenced by human actions" (Earth System Science Committee, 1988, p. II). This paper describes the developed in response to change.
Canadian Global Change Program which is being the above environmental challenges posed by global
H I S T O R Y AND ORGANIZATION
The first meeting of Canadian scientists devoted to global change took place in December, 1985. A report prepared from this meeting formed the basis of Canadian support in establishing the International Geosphere - Biosphere Programme by the International Council of Scientific Unions in September, 1986. In December, 1986 a Steering Committee was established in Canada under the auspices of the Royal Society. Initially, three main working groups (Terrestrial and Atmospheric Interactions W.G., Marine and Atmospheric Interactions W.G., Arctic W.G.) and one resource group (Remote Sensing Technical Group) were established. More recently, other groups are being added, including a working group on global models and processes and a resource group on data and information systems. It is expected that the organizational structure will be modified further as the Program develops. AREAS OF EMPHASIS Discussions among scientists so far have suggested that the focus should be placed on a relatively limited number of issues that are of special importance to Canada. The choice of these issues is determined principally by the susceptibility of the various ecosystem components to global change and the impact of that change, environmentally as well as socially. The anticipated changes of the global environment would ultimately affect the lives of people and the surrounding terrestrial environment. In addition, land resources constitute a significant part of Canada's economy, and global change would thus have direct economic consequences. For these reasons, the assessment of the relationship of global change and terrestrial ecosystems of Canada has special significance. Several priority problem areas have been identified so far. The boreal ecosystem has attracted most attention to date. The forest, wetland, and surface water (lakes and rivers) components are closely involved in the biochemical cycles of carbon, nitrogen and related elements as well as in the hydrological cycle. Globally, the boreal ecosystem forms a dark belt around the world which affects the shortwave and longwave radiation balance as well as the interaction with the atmospheric boundary layer (through its effect on planetary roughness, hydrologic cycle, etc.). From the economic viewpoint, environmental change would likely modify the ability of commercial species to grow rapidly, and it could even make certain tree species unsuitable for economic exploitation. The wetlands in the boreal region store large amounts of carbon which might be released under certain climatic conditions, thus contributing to greenhouse warming. The prairie ecosystem is another area of considerable interest. The interest in this ecosystem has been stimulated by the predictions of General Circulation Models (GCM) which suggest that substantial increases in temperature and soil dryness in the Canadian prairies are to be expected as a consequence of the greenhouse warming effect. The prairies presently provide much of Canada's cereal production and thereby also influence secondary industries such as transportation and food processing. Continuing viability of the production and the preservation of longterm productive capability are thus major global change issues affecting Canadian agriculture. In addition, prairie wetlands have important ecosystem role in the hydrologic cycle and as waterfowl habitats (the latter also having a significant economic aspect). Montane areas, particularly ecosystems in the Rocky Mountains of western Canada, have characteristics that would be affected by environmental change.
Canadian Global Change Program
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Of p r i m a r y c o n c e r n are v e g e t a t i o n and h y d r o l o g i c resources, i n c l u d i n g snow. C l i m a t i c changes w o u l d m o d i f y t e m p e r a t u r e and m o i s t u r e regimes of these areas w h i c h in turn c o u l d affect the f u n c t i o n i n g and e c o n o m i c p r o d u c t i v i t y (wood, h y d r o e l e c t r i c power) of these regions. Several aspects of the t e r r e s t r i a l e c o s y s t e m s of C a n a d a have been i d e n t i f i e d as requiring detailed studies. The p o t e n t i a l effect of global change on c o m m e r c i a l f o r e s t r y needs to be evaluated. This includes the c h a n g e s in growth and productivity of present commercial species, and the p o s s i b l e r e q u i r e m e n t for the i n t r o d u c t i o n of d i f f e r e n t species that w o u l d be b e t t e r adapted to the new conditions. Modified hydrological conditions within f o r e s t e d areas c o u l d also require different forest m a n a g e m e n t practices. Another area for detailed studies are longterm changes in vegetation distribution resulting from modified vegetation succession s e q u e n c e s and z o n a t i o n patterns. C l i m a t i c change w o u l d l i k e l y also bring about changes in the f r e q u e n c y and d i s t r i b u t i o n of forest fires and in the p a t t e r n of damage by insects and diseases; both p h e n o m e n a w o u l d have a direct e c o n o m i c impact and thus require m u c h better understanding. Ultimately, the a s s u m p t i o n s u n d e r l y i n g the a s s e s s m e n t of a v a l u e that society p l a c e s on forests may need to be re-examined. For example, the mere e x i s t e n c e of a forest may be of c o m p a r a b l e value to the e n v i r o n m e n t and to the h u m a n species ( e s p e c i a l l y in the long term and when considered as a component of the global boreal ecosystem) than the e c o n o m i c v a l u e of the wood that can be harvested. The r e s p o n s e of w e t l a n d s to c l i m a t i c change needs to be evaluated. Possible c o n s e q u e n c e s include species and zonation changes. The p a l e o e c o l o g i c a l record preserved in wetlands provides a source of information. Another important aspect is the wetlands budget of certain elements (especially carbon) and the p o s s i b l e release of these e l e m e n t s following a s u b s t a n t i a l e n v i r o n m e n t a l change, e.g. drying up of wetlands. In the prairies, the impact of change on the p r o d u c t i o n and m a n a g e m e n t of a g r i c u l t u r a l e c o s y s t e m s is of g r e a t e s t concern. The above studies need to be s u p p l e m e n t e d with a detailed evaluation of the c l i m a t o l o g i c a l d a t a c o l l e c t e d across C a n a d a to date in terms of d e t e c t a b l e signals of c l i m a t i c change. Canadian oceanographers have long been studying processes that are of importance from the viewpoint of global change. For example, the o c e a n drilling program yields i n f o r m a t i o n on past environmental conditions which can be used in reconstructing climate history. The u n d e r s t a n d i n g of ocean p r o c e s s e s is n e c e s s a r y for predicting future climatic trends. Two new programs closely r e l a t e d to the IGBP are c u r r e n t l y under preparation, the World Ocean Circulation Experiment (WOCE), and the Joint Global O c e a n Flux St u d y (J-GOFS). WOCE is c o n c e r n e d w i t h the study of o c e a n c u r r e n t s while the goal of J-GOFS is to q u a n t i f y the p r i m a r y ocean productivity (phytoplankton biomass). U n f o r t u n a t e l y , J-GOFS does not p r e s e n t l y include the A r c t i c Ocean. C a n a d i a n s c i e n t i s t s are p a r t i c i p a t i n g in the p l a n n i n g of these two programs. In addition, it is a n t i c i p a t e d that s u p p l e m e n t a r y a c t i v i t i e s will be p r o p o s e d as part of the CGCP. A n u m b e r of r e s e a r c h themes that are important to global change have been i d e n t i f i e d for the c i r c u m p o l a r A r c t i c r e g i o n (Anonymous, 1988). T h e y include the extent of sea ice and its s e n s i t i v i t y to a n t h r o p o g e n i c p e r t u r b a t i o n s ; A r c t i c haze; c h a n g e s in g l a c i e r s and ice sheets and in sea level; the b i o t a in r e l a t i o n to the ocean ice margin; the role of peatlands in the biogeochemical cycling; changes in ground ice resulting from climatic changes; and the p a l e o e n v i r o n m e n t a l record. In Canada, four r e s e a r c h areas have been identified for detailed studies in the Arctic. These are the problem of climatic change in high latitudes and its effect on that environment; the q u e s t i o n of p e r m a f r o s t and its role in biological, c h e m i c a l and p h y s i c a l p r o c e s s e s in the c h a n g i n g Arctic; the c o n s e q u e n c e of c h a n g i n g h a b i t a t s on terrestrial vegetation in the A r c t i c and Subarctic; and sea ice as passive as well as dynamic environmental factor (including the r e l a t i o n s h i p b e t w e e n land, sea, air and biota). REMOTE
SENSING
CONTRIBUTION
Satellite observations are expected to play a major role in the IGBP (Rasool,1987). This is because this program will require frequent o b s e r v a t i o n s of the globe w h i c h cannot r e a l i s t i c a l l y be o b t a i n e d in any o t h e r way. As P r o f e s s o r T. Malone stated (Malone, 1988, p. 31): "..We stand on the threshold of a renaissance in the s c i e n c e s c o n c e r n e d w i t h the Planet Earth, i n c l u d i n g its fauna, flora and the humans who call it t h e i r home... This renaissance has its origins in no small part - i n t h e p o w e r f u l
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J. Cihlar and M. Dence
observational capability provided by space science and technology. Its fulfillment is conditioned in large measure on the initiative, imagination, and active i n v o l v e m e n t of the i n t e r n a t i o n a l c o m m u n i t y of space agencies. This i n v o l v e m e n t is more than m e r e l y s u p p l y i n g the p r o m i s i n g new t e c h n o l o g y of "remote sensing". It will require intensive p a r t i c i p a t i o n in the b i r t h of a sweeping new science, one that p r o m i s e s to i l l u m i n a t e over the next few decades the intimate i n t e r a c t i o n of the g e o s p h e r e and b i o s p h e r e and the role of h u m a n a c t i v i t y in inducing global change..". The importance of satellite o b s e r v a t i o n s is high e s p e c i a l l y for C a n a d a whose large n o r t h e r n t e r r i t o r i e s have a very sparse m e a s u r e m e n t n e t w o r k and where data a c q u i s i t i o n by t r a d i t i o n a l means is prohibitively expensive. To be fully effective, the satellite m e a s u r e m e n t s must be c o m p l e m e n t e d by a welld e s i g n e d surface data a c q u i s i t i o n program. With these c o n s i d e r a t i o n s in mind, the Remote Sensing Technical Group proposed a p r o g r a m for using satellite o b s e r v a t i o n s in the CGCF. The p r o g r a m is based on the following guiding principles. Remote global active
sensing efforts should be c o n c e n t r a t e d on p r o b l e m s important to change, unique to Canada, and those where Canada is a l r e a d y or can make a v a l u a b l e contribution.
The Canadian remote sensing effort must be closely linked with i n t e r n a t i o n a l activities, to c o n t r i b u t e as well as to benefit. This entails p a r t i c i p a t i o n in projects, access to g l o b a l / r e g i o n a l data, and c o n t r i b u t i o n to p l a n n i n g and e x p l o i t a t i o n of future missions. During the o p e r a t i o n a l phase of the CGCP, s a t e l l i t e s will ("wall-to-wall") c o v e r a g e of C a n a d a at a coarse r e s o l u t i o n ("local") c o v e r a g e at high resolution.
p r o v i d e full and s e l e c t e d
The key to a successful use of r e m o t e l y sensed data is the a v a i l a b i l i t y of a c c u r a t e i n v e r s i o n models. C o n c e n t r a t e d effort is needed in the near future to d e v e l o p and/or v a l i d a t e such models. Remote sensing data show what is now; therefore, their linked w i t h a p p r o p r i a t e e n v i r o n m e n t a l (process) models.
use
must he
The above p r i n c i p l e s suggest that in the next several years, c o n c e n t r a t e d effort will be needed to d e v e l o p and test the a p p r o p r i a t e i n v e r s i o n models. In addition, systems and p r o c e d u r e s for h a n d l i n g the satellite data for CGCP p u r p o s e s must he d e v e l o p e d and tested. In the follow - on o p e r a t i o n a l p e r i o d (assumed to be about 20 years), s a t e l l i t e data w o u l d be r o u t i n e l y received, archived, and p r o c e s s e d into g e o p h y s i c a l variables. The results w o u l d be entered into advanced geographic information systems for integration, a n a l y s i s and modeling. The Remote Sensing T e c h n i c a l Group proposed e m p h a s i s (Cihlar e t a ! . , 1988):
the following
initial
areas
of
Satellite data c a l i b r a t i o n and the v a l i d a t i o n of a t m o s p h e r i c c o r r e c t i o n models, as a key area that affects all a p p l i c a t i o n s of the s a t e l l i t e measurements. Mapping albedo and net radiation from satellite images for climate studies, including the input of the results into GCMs for e v a l u a t i n g the effects of spatial v a r i a b i l i t y of albedo and its change on climate model predictions. Monitoring and change
terrestrial detection.
vegetation
of Canada,
with
emphasis
Monitoring atmospheric c o n s t i t u e n t s - e s p e c i a l l y ozone, c a r b o n monoxide, methane, and c h l o r o f l u o r o c a r b o n s . *
Estimation
of oceans
productivity
*
Cryosphere
monitoring
including
and m e a s u r e m e n t
sea ice,
glaciers,
on p h y t o m a s s
c a r b o n dioxide,
of o c e a n currents. snow,
and permafrost.
It is e x p e c t e d that these initial p r o j e c t s will be f o l l o w e d by others as the program develops. Furthermore, the satellite observations will he i n c o r p o r a t e d in an overall approach as the detailed project plans are d e v e l o p e d by the v a r i o u s w o r k i n g groups u n d e r the CGCP.
Canadian Global Change Program
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An important c o m p o n e n t of a program of global change will be a s y s t e m for storing, accessing, processing and analysing satellite and other e n v i r o n m e n t a l data. The c o n c e p t for such a system, called GCNet, has been o u t l i n e d (Cihlar et a~., 1988). GCNet is a network linking i m p o r t a n t d a t a bases w i t h a n a l y s i s and m o d e l i n g capabilities. A user will be able to access any of the d a t a bases to d e t e r m i n e w h e t h e r it c o n t a i n s data of interest, to r e t r i e v e the r e q u i r e d data, and to carry out a p p r o p r i a t e analyses. GCNet will thus have a series of nodes (which could he Data, Analysis, or C o m b i n e d nodes) linked by a c o m m u n i c a t i o n system. A s t a n d a r d p r o t o c o l will f a c i l i t a t e the c o m m u n i c a t i o n by a user t h r o u g h o u t the system. It is highly desirable that the Canadian system be compatible with similar systems of other c o u n t r i e s so that other data bases can also be accessed. SUMMARY The C a n a d i a n Global Change P r o g r a m is p r e s e n t l y at the p l a n n i n g stage. The individual w o r k i n g groups have i d e n t i f i e d a l i m i t e d set of p r i o r i t y areas in terrestrial, marine, and A r c t i c ecosystems that require d e t a i l e d studies. The c r i t e r i a for s e l e c t i n g these areas include i m p o r t a n c e to global change p r o c e s s e s and r e l e v a n c e to Canada. Such focus is n e c e s s a r y for the p r o g r a m to y i e l d i n f o r m a t i o n of value to science as well as to the society. Satellite observations will be an important component of the CGCP, c o m p l e m e n t e d by detailed studies and measurements at carefully selected ground observatories. An initial set of p r o j e c t s e m p l o y i n g s a t e l l i t e data has been identified. To carry out the CGCP successfully, an a p p r o p r i a t e s y s t e m c o n s i s t i n g of data bases and an a l y s i s f a c i l i t i e s must be available. A c o n c e p t of GCNet has been p r o p o s e d w h i c h a d d r e s s e s this requirement. C a n a d i a n s c i e n t i s t s r e c o g n i z e the importance of international collaboration in p r e p a r i n g the d e f i n i t i v e plan for the IGBP. To achieve the u n d e r s t a n d i n g at the global scale, the efforts and c o n t r i b u t i o n s of individual c o u n t r i e s must be coordinated, integrated, and u l t i m a t e l y fused into a c o h e r e n t p i c t u r e of the E a r t h as one system. This is a very challenging task for the international scientific community as well as for political bodies at na t i o n a l and i n t e r n a t i o n a l levels. ACKNOWLEDGEMENTS In p r e p a r i n g this paper, the a u t h o r s have used results of d i s c u s s i o n s by three W o r k i n g Groups reporting to the Royal S o c i e t y of C a n a d a ( T e r r e s t r i a l A t m o s p h e r i c I n t e r a c t i o n s WG led by Prof. T. Hutchinson; Marine - A t m o s p h e r i c Interactions WG led by Dr. A. Longhurst; and the Arctic WG led by Dr. F. Roots), as well as draft documents which are not yet r e a d y for publication. These e s s e n t i a l c o n t r i b u t i o n s are g r e a t f u l l y acknowledged. REFERENCES Anonymous. 1988. c o m p o n e n t in the IGBP. OIES-4, UCAR, Boulder,
Arctic interactions: recommendations Office for I n t e r d i s c i p l i n a r y Earth Colorado. 70p.
for an A r c t i c Studies, R e p o r t
Cihlar, J., E. LeDrew, H. Edel, W. Evans, D. McKay, L. McNutt, and A. Royer. 1988. C o n t r i b u t i o n of s a t e l l i t e o b s e r v a t i o n s to the C a n a d i a n Global Change Program. A report to the Royal S o c i e t y of C a n a d a by the Remote Sensing T e c h n i c a l Group, July. 32p. C o m m i t t e e on Space 1987. 138p. Earth view.
Research.
1987.
Information
Bulletin
No.
108,
April
System S c i e n c e s Committee. 1988. Earth system science. A closer N a t i o n a l A e r o n a u t i c s and Space A d m i n i s t r a t i o n , Washington, D.C. 208p.
Malone, T.F. 1988. The I n t e r n a t i o n a l Space Year (ISY) and The I n t e r n a t i o n a l Geosphere - Biosphere Program (IGBP). Report of the ISY M i s s i o n TO Planet E a r t h Conference, Durham, New Hampshire, 29 April to 1 May, pp. 31-34. Manabe, induced
S., and R.T. by an i n c r e a s e
Rasool, S.I. global change.
(Ed). Advances
Wetherald. 1986. Reduction in a t m o s p h e r i c c a r b o n dioxide. 1987. in Space
in summer soil w e t n e s s Science 232: 626-628.
P o t e n t i a l of remote sensing R e s e a r c h 7(1). 96p.
for the
study of
9, No. 7, pp. (7)23-(7)27, 1989 Printed in Great Britain. All rights reserved.
THE C A N A D I A N PROGRAM
0273-1177/89 $0.00 +.50 Copyright © 1989 COSPAR
GLOBAL CHANGE
J. Cihlar* and M. Dence** *Canada Centre for Remote Sensing, 2464 Sheffield Road, Ottawa, Ontario, K1A OY7, Canada **Royal Society of Canada, 344 Wellington Street, Suite 3006, Ottawa, Ontario, K1A ON4, Canada
ABSTRACT This p a p e r d e s c r i b e s the p r o p o s e d C a n a d i a n c o n t r i b u t i o n to the I n t e r n a t i o n a l G e o s p h e r e - B i o s p h e r e Program. While the C a n a d i a n p r o g r a m is at the p l a n n i n g stage, m a j o r themes for focussed effort have been identified in three domains: terrestrial - atmospheric interactions, marine - atmospheric interactions, and the A r c t i c r e g i o n as an ecosystem. The p a p e r further e l a b o r a t e s on the c o n t r i b u t i o n of s a t e l l i t e o b s e r v a t i o n s to this p r o g r a m by o u t l i n i n g g u i d i n g p r i n c i p l e s and p r o p o s e d remote sensing activities. INTRODUCTION The e n v i r o n m e n t at the Earth's surface appears to be u n d e r g o i n g c h a n g e s that may have h i g h l y s i g n i f i c a n t c o n s e q u e n c e s for the w e l l - b e i n g and p r o s p e r i t y of the h u m a n species. These changes are related to various key c o m p o n e n t s of the earth system including its atmosphere, oceans, and land ecosystems. E x a m p l e s of such changes are potential greenhouse warming caused by the increase in c a r b o n dioxide c o n c e n t r a t i o n in the a t m o s p h e r e as well as those of other r a d i a t i v e l y active gases including m e t h a n e and c h l o r o f l u o r o c a r b o n s ; d e f o r e s t a t i o n and desertification occurring in v a r i o u s parts of the world; and the c o n t i n u i n g d e t e r i o r a t i o n of soil productivity. Some of these are e x p e c t e d to lead to l o n g t e r m m o d i f i c a t i o n s of the e n v i r o n m e n t a l c o n d i t i o n s at or near the Earth's surface. For instance, model p r e d i c t i o n s have shown that the doubling of CO2 in the atmosphere could in central C a n a d a increase surface t e m p e r a t u r e during the summer months of up to 9 d e g r e e s C e l s i u s and reduce the available soil water by more than 50% (Manabe and Wetherald, 1986). The rise in sea level with resulting flooding of coastal cities around the world, modified patterns of the hydrological cycle, and g e o g r a p h i c a l shifts in vegetation distribution are examples of p o s s i b l e future e n v i r o n m e n t a l changes. As a h i g h - l a t i t u d e country, C a n a d a has c e r t a i n d i s t i n c t i v e e n v i r o n m e n t a l and c l i m a t i c features w h i c h are c a u s e d by the Sun - E a r t h geometry, the p l a n e t a r y m o t i o n of the Earth, and the regional g e o l o g i c a l history. The i n t e r r e l a t e d consequences of these factors include strong regional heat loss, thus r e q u i r i n g transport of heat from low latitudes; important t r a n s f e r p r o c e s s e s c o n c e r n e d w i t h r a d i a t i o n (albedo) and heat (phase changes) r e s u l t i n g from the p r e s e n c e of snow and ice; and s e n s i t i v e i n t e r a c t i o n s b e t w e e n o c e a n current ( e s p e c i a l l y in the A r c t i c Ocean), p o l a r and t e m p e r a t e air masses, and the regional climate. In addition, v a r i o u s C a n a d i a n e c o s y s t e m s are of special significance for global change. These include the cold water marine ecosystems, the boreal forest and wetlands, and the anthropogenically m o d i f i e d e c o s y s t e m s at lower l a t i t u d e s (a " 5 0 0 - y e a r record of change"). As s c i e n t i s t s a t t e m p t to more p r e c i s e l y define the d i r e c t i o n and m a g n i t u d e of the future e n v i r o n m e n t a l changes, it has become i n c r e a s i n g l y o b v i o u s that our u n d e r s t a n d i n g of the p r o c e s s e s o c c u r r i n g at and near the E a r t h ' s surface is inadequate. This realization in turn led to the f o r m u l a t i o n of v a r i o u s r e s e a r c h p r o g r a m s a i m e d at filling the gaps in the u n d e r s t a n d i n g of the E a r t h and of the c h a n g e s that occur in this system. Two p r o g r a m s are n o t a b l e for their scope, the I n t e r n a t i o n a l G e o s p h e r e - B i o s p h e r e Program: A S t u d y of G l o b a l C h a n g e and the U.S. E a r t h S y s t e m Science program. Both p r o g r a m s focus
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on global change. The objective of the International Geosphere - Biosphere Program (IGBP) is "to obtain scientific understanding of the Earth system by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to evolve in the future" (Committee on Space Research, 1987, p. 18). The goal of the Earth System Science program is "to describe and understand the interactive physical, chemical, and biological processes that regulate the Earth's unique environment for life, the changes that are occurring in this system, and the manner in which they are influenced by human actions" (Earth System Science Committee, 1988, p. II). This paper describes the developed in response to change.
Canadian Global Change Program which is being the above environmental challenges posed by global
H I S T O R Y AND ORGANIZATION
The first meeting of Canadian scientists devoted to global change took place in December, 1985. A report prepared from this meeting formed the basis of Canadian support in establishing the International Geosphere - Biosphere Programme by the International Council of Scientific Unions in September, 1986. In December, 1986 a Steering Committee was established in Canada under the auspices of the Royal Society. Initially, three main working groups (Terrestrial and Atmospheric Interactions W.G., Marine and Atmospheric Interactions W.G., Arctic W.G.) and one resource group (Remote Sensing Technical Group) were established. More recently, other groups are being added, including a working group on global models and processes and a resource group on data and information systems. It is expected that the organizational structure will be modified further as the Program develops. AREAS OF EMPHASIS Discussions among scientists so far have suggested that the focus should be placed on a relatively limited number of issues that are of special importance to Canada. The choice of these issues is determined principally by the susceptibility of the various ecosystem components to global change and the impact of that change, environmentally as well as socially. The anticipated changes of the global environment would ultimately affect the lives of people and the surrounding terrestrial environment. In addition, land resources constitute a significant part of Canada's economy, and global change would thus have direct economic consequences. For these reasons, the assessment of the relationship of global change and terrestrial ecosystems of Canada has special significance. Several priority problem areas have been identified so far. The boreal ecosystem has attracted most attention to date. The forest, wetland, and surface water (lakes and rivers) components are closely involved in the biochemical cycles of carbon, nitrogen and related elements as well as in the hydrological cycle. Globally, the boreal ecosystem forms a dark belt around the world which affects the shortwave and longwave radiation balance as well as the interaction with the atmospheric boundary layer (through its effect on planetary roughness, hydrologic cycle, etc.). From the economic viewpoint, environmental change would likely modify the ability of commercial species to grow rapidly, and it could even make certain tree species unsuitable for economic exploitation. The wetlands in the boreal region store large amounts of carbon which might be released under certain climatic conditions, thus contributing to greenhouse warming. The prairie ecosystem is another area of considerable interest. The interest in this ecosystem has been stimulated by the predictions of General Circulation Models (GCM) which suggest that substantial increases in temperature and soil dryness in the Canadian prairies are to be expected as a consequence of the greenhouse warming effect. The prairies presently provide much of Canada's cereal production and thereby also influence secondary industries such as transportation and food processing. Continuing viability of the production and the preservation of longterm productive capability are thus major global change issues affecting Canadian agriculture. In addition, prairie wetlands have important ecosystem role in the hydrologic cycle and as waterfowl habitats (the latter also having a significant economic aspect). Montane areas, particularly ecosystems in the Rocky Mountains of western Canada, have characteristics that would be affected by environmental change.
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Of p r i m a r y c o n c e r n are v e g e t a t i o n and h y d r o l o g i c resources, i n c l u d i n g snow. C l i m a t i c changes w o u l d m o d i f y t e m p e r a t u r e and m o i s t u r e regimes of these areas w h i c h in turn c o u l d affect the f u n c t i o n i n g and e c o n o m i c p r o d u c t i v i t y (wood, h y d r o e l e c t r i c power) of these regions. Several aspects of the t e r r e s t r i a l e c o s y s t e m s of C a n a d a have been i d e n t i f i e d as requiring detailed studies. The p o t e n t i a l effect of global change on c o m m e r c i a l f o r e s t r y needs to be evaluated. This includes the c h a n g e s in growth and productivity of present commercial species, and the p o s s i b l e r e q u i r e m e n t for the i n t r o d u c t i o n of d i f f e r e n t species that w o u l d be b e t t e r adapted to the new conditions. Modified hydrological conditions within f o r e s t e d areas c o u l d also require different forest m a n a g e m e n t practices. Another area for detailed studies are longterm changes in vegetation distribution resulting from modified vegetation succession s e q u e n c e s and z o n a t i o n patterns. C l i m a t i c change w o u l d l i k e l y also bring about changes in the f r e q u e n c y and d i s t r i b u t i o n of forest fires and in the p a t t e r n of damage by insects and diseases; both p h e n o m e n a w o u l d have a direct e c o n o m i c impact and thus require m u c h better understanding. Ultimately, the a s s u m p t i o n s u n d e r l y i n g the a s s e s s m e n t of a v a l u e that society p l a c e s on forests may need to be re-examined. For example, the mere e x i s t e n c e of a forest may be of c o m p a r a b l e value to the e n v i r o n m e n t and to the h u m a n species ( e s p e c i a l l y in the long term and when considered as a component of the global boreal ecosystem) than the e c o n o m i c v a l u e of the wood that can be harvested. The r e s p o n s e of w e t l a n d s to c l i m a t i c change needs to be evaluated. Possible c o n s e q u e n c e s include species and zonation changes. The p a l e o e c o l o g i c a l record preserved in wetlands provides a source of information. Another important aspect is the wetlands budget of certain elements (especially carbon) and the p o s s i b l e release of these e l e m e n t s following a s u b s t a n t i a l e n v i r o n m e n t a l change, e.g. drying up of wetlands. In the prairies, the impact of change on the p r o d u c t i o n and m a n a g e m e n t of a g r i c u l t u r a l e c o s y s t e m s is of g r e a t e s t concern. The above studies need to be s u p p l e m e n t e d with a detailed evaluation of the c l i m a t o l o g i c a l d a t a c o l l e c t e d across C a n a d a to date in terms of d e t e c t a b l e signals of c l i m a t i c change. Canadian oceanographers have long been studying processes that are of importance from the viewpoint of global change. For example, the o c e a n drilling program yields i n f o r m a t i o n on past environmental conditions which can be used in reconstructing climate history. The u n d e r s t a n d i n g of ocean p r o c e s s e s is n e c e s s a r y for predicting future climatic trends. Two new programs closely r e l a t e d to the IGBP are c u r r e n t l y under preparation, the World Ocean Circulation Experiment (WOCE), and the Joint Global O c e a n Flux St u d y (J-GOFS). WOCE is c o n c e r n e d w i t h the study of o c e a n c u r r e n t s while the goal of J-GOFS is to q u a n t i f y the p r i m a r y ocean productivity (phytoplankton biomass). U n f o r t u n a t e l y , J-GOFS does not p r e s e n t l y include the A r c t i c Ocean. C a n a d i a n s c i e n t i s t s are p a r t i c i p a t i n g in the p l a n n i n g of these two programs. In addition, it is a n t i c i p a t e d that s u p p l e m e n t a r y a c t i v i t i e s will be p r o p o s e d as part of the CGCP. A n u m b e r of r e s e a r c h themes that are important to global change have been i d e n t i f i e d for the c i r c u m p o l a r A r c t i c r e g i o n (Anonymous, 1988). T h e y include the extent of sea ice and its s e n s i t i v i t y to a n t h r o p o g e n i c p e r t u r b a t i o n s ; A r c t i c haze; c h a n g e s in g l a c i e r s and ice sheets and in sea level; the b i o t a in r e l a t i o n to the ocean ice margin; the role of peatlands in the biogeochemical cycling; changes in ground ice resulting from climatic changes; and the p a l e o e n v i r o n m e n t a l record. In Canada, four r e s e a r c h areas have been identified for detailed studies in the Arctic. These are the problem of climatic change in high latitudes and its effect on that environment; the q u e s t i o n of p e r m a f r o s t and its role in biological, c h e m i c a l and p h y s i c a l p r o c e s s e s in the c h a n g i n g Arctic; the c o n s e q u e n c e of c h a n g i n g h a b i t a t s on terrestrial vegetation in the A r c t i c and Subarctic; and sea ice as passive as well as dynamic environmental factor (including the r e l a t i o n s h i p b e t w e e n land, sea, air and biota). REMOTE
SENSING
CONTRIBUTION
Satellite observations are expected to play a major role in the IGBP (Rasool,1987). This is because this program will require frequent o b s e r v a t i o n s of the globe w h i c h cannot r e a l i s t i c a l l y be o b t a i n e d in any o t h e r way. As P r o f e s s o r T. Malone stated (Malone, 1988, p. 31): "..We stand on the threshold of a renaissance in the s c i e n c e s c o n c e r n e d w i t h the Planet Earth, i n c l u d i n g its fauna, flora and the humans who call it t h e i r home... This renaissance has its origins in no small part - i n t h e p o w e r f u l
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J. Cihlar and M. Dence
observational capability provided by space science and technology. Its fulfillment is conditioned in large measure on the initiative, imagination, and active i n v o l v e m e n t of the i n t e r n a t i o n a l c o m m u n i t y of space agencies. This i n v o l v e m e n t is more than m e r e l y s u p p l y i n g the p r o m i s i n g new t e c h n o l o g y of "remote sensing". It will require intensive p a r t i c i p a t i o n in the b i r t h of a sweeping new science, one that p r o m i s e s to i l l u m i n a t e over the next few decades the intimate i n t e r a c t i o n of the g e o s p h e r e and b i o s p h e r e and the role of h u m a n a c t i v i t y in inducing global change..". The importance of satellite o b s e r v a t i o n s is high e s p e c i a l l y for C a n a d a whose large n o r t h e r n t e r r i t o r i e s have a very sparse m e a s u r e m e n t n e t w o r k and where data a c q u i s i t i o n by t r a d i t i o n a l means is prohibitively expensive. To be fully effective, the satellite m e a s u r e m e n t s must be c o m p l e m e n t e d by a welld e s i g n e d surface data a c q u i s i t i o n program. With these c o n s i d e r a t i o n s in mind, the Remote Sensing Technical Group proposed a p r o g r a m for using satellite o b s e r v a t i o n s in the CGCF. The p r o g r a m is based on the following guiding principles. Remote global active
sensing efforts should be c o n c e n t r a t e d on p r o b l e m s important to change, unique to Canada, and those where Canada is a l r e a d y or can make a v a l u a b l e contribution.
The Canadian remote sensing effort must be closely linked with i n t e r n a t i o n a l activities, to c o n t r i b u t e as well as to benefit. This entails p a r t i c i p a t i o n in projects, access to g l o b a l / r e g i o n a l data, and c o n t r i b u t i o n to p l a n n i n g and e x p l o i t a t i o n of future missions. During the o p e r a t i o n a l phase of the CGCP, s a t e l l i t e s will ("wall-to-wall") c o v e r a g e of C a n a d a at a coarse r e s o l u t i o n ("local") c o v e r a g e at high resolution.
p r o v i d e full and s e l e c t e d
The key to a successful use of r e m o t e l y sensed data is the a v a i l a b i l i t y of a c c u r a t e i n v e r s i o n models. C o n c e n t r a t e d effort is needed in the near future to d e v e l o p and/or v a l i d a t e such models. Remote sensing data show what is now; therefore, their linked w i t h a p p r o p r i a t e e n v i r o n m e n t a l (process) models.
use
must he
The above p r i n c i p l e s suggest that in the next several years, c o n c e n t r a t e d effort will be needed to d e v e l o p and test the a p p r o p r i a t e i n v e r s i o n models. In addition, systems and p r o c e d u r e s for h a n d l i n g the satellite data for CGCP p u r p o s e s must he d e v e l o p e d and tested. In the follow - on o p e r a t i o n a l p e r i o d (assumed to be about 20 years), s a t e l l i t e data w o u l d be r o u t i n e l y received, archived, and p r o c e s s e d into g e o p h y s i c a l variables. The results w o u l d be entered into advanced geographic information systems for integration, a n a l y s i s and modeling. The Remote Sensing T e c h n i c a l Group proposed e m p h a s i s (Cihlar e t a ! . , 1988):
the following
initial
areas
of
Satellite data c a l i b r a t i o n and the v a l i d a t i o n of a t m o s p h e r i c c o r r e c t i o n models, as a key area that affects all a p p l i c a t i o n s of the s a t e l l i t e measurements. Mapping albedo and net radiation from satellite images for climate studies, including the input of the results into GCMs for e v a l u a t i n g the effects of spatial v a r i a b i l i t y of albedo and its change on climate model predictions. Monitoring and change
terrestrial detection.
vegetation
of Canada,
with
emphasis
Monitoring atmospheric c o n s t i t u e n t s - e s p e c i a l l y ozone, c a r b o n monoxide, methane, and c h l o r o f l u o r o c a r b o n s . *
Estimation
of oceans
productivity
*
Cryosphere
monitoring
including
and m e a s u r e m e n t
sea ice,
glaciers,
on p h y t o m a s s
c a r b o n dioxide,
of o c e a n currents. snow,
and permafrost.
It is e x p e c t e d that these initial p r o j e c t s will be f o l l o w e d by others as the program develops. Furthermore, the satellite observations will he i n c o r p o r a t e d in an overall approach as the detailed project plans are d e v e l o p e d by the v a r i o u s w o r k i n g groups u n d e r the CGCP.
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An important c o m p o n e n t of a program of global change will be a s y s t e m for storing, accessing, processing and analysing satellite and other e n v i r o n m e n t a l data. The c o n c e p t for such a system, called GCNet, has been o u t l i n e d (Cihlar et a~., 1988). GCNet is a network linking i m p o r t a n t d a t a bases w i t h a n a l y s i s and m o d e l i n g capabilities. A user will be able to access any of the d a t a bases to d e t e r m i n e w h e t h e r it c o n t a i n s data of interest, to r e t r i e v e the r e q u i r e d data, and to carry out a p p r o p r i a t e analyses. GCNet will thus have a series of nodes (which could he Data, Analysis, or C o m b i n e d nodes) linked by a c o m m u n i c a t i o n system. A s t a n d a r d p r o t o c o l will f a c i l i t a t e the c o m m u n i c a t i o n by a user t h r o u g h o u t the system. It is highly desirable that the Canadian system be compatible with similar systems of other c o u n t r i e s so that other data bases can also be accessed. SUMMARY The C a n a d i a n Global Change P r o g r a m is p r e s e n t l y at the p l a n n i n g stage. The individual w o r k i n g groups have i d e n t i f i e d a l i m i t e d set of p r i o r i t y areas in terrestrial, marine, and A r c t i c ecosystems that require d e t a i l e d studies. The c r i t e r i a for s e l e c t i n g these areas include i m p o r t a n c e to global change p r o c e s s e s and r e l e v a n c e to Canada. Such focus is n e c e s s a r y for the p r o g r a m to y i e l d i n f o r m a t i o n of value to science as well as to the society. Satellite observations will be an important component of the CGCP, c o m p l e m e n t e d by detailed studies and measurements at carefully selected ground observatories. An initial set of p r o j e c t s e m p l o y i n g s a t e l l i t e data has been identified. To carry out the CGCP successfully, an a p p r o p r i a t e s y s t e m c o n s i s t i n g of data bases and an a l y s i s f a c i l i t i e s must be available. A c o n c e p t of GCNet has been p r o p o s e d w h i c h a d d r e s s e s this requirement. C a n a d i a n s c i e n t i s t s r e c o g n i z e the importance of international collaboration in p r e p a r i n g the d e f i n i t i v e plan for the IGBP. To achieve the u n d e r s t a n d i n g at the global scale, the efforts and c o n t r i b u t i o n s of individual c o u n t r i e s must be coordinated, integrated, and u l t i m a t e l y fused into a c o h e r e n t p i c t u r e of the E a r t h as one system. This is a very challenging task for the international scientific community as well as for political bodies at na t i o n a l and i n t e r n a t i o n a l levels. ACKNOWLEDGEMENTS In p r e p a r i n g this paper, the a u t h o r s have used results of d i s c u s s i o n s by three W o r k i n g Groups reporting to the Royal S o c i e t y of C a n a d a ( T e r r e s t r i a l A t m o s p h e r i c I n t e r a c t i o n s WG led by Prof. T. Hutchinson; Marine - A t m o s p h e r i c Interactions WG led by Dr. A. Longhurst; and the Arctic WG led by Dr. F. Roots), as well as draft documents which are not yet r e a d y for publication. These e s s e n t i a l c o n t r i b u t i o n s are g r e a t f u l l y acknowledged. REFERENCES Anonymous. 1988. c o m p o n e n t in the IGBP. OIES-4, UCAR, Boulder,
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