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A low-carbon future starts here
INSTANT EXPERT / COPENHAGEN Carbon budget for 2°C
What we’ve used
The world’s politicians and climate scientists have settled on 2 °C as the threshold for “dangerous” global warming. To stay below this we must emit no more than 750,000Mt of carbon in total. Sometime in 2006 we emitted the 500,000th megatonne
megatonnes of carbon
Deforestation 200,000Mt European Union 81,700Mt Since the beginning of the industrial revolution in the mid-1700s, humans have emitted over 500,000Mt of carbon. Roughly 200,000Mt has come from uprooting forests. The remainder is the result of burning fossil fuels and making cement, mostly in rich nations
US 91,200Mt
China 27,800Mt Canada 6800Mt Australia 3500Mt
Rest of world 66,000Mt
India 8300Mt
Africa 8200Mt
Latin America & Caribbean 12,500Mt Brazil 2600Mt
Climate scientists estimate that in order to have a 75% chance of avoiding more than 2°C of global warming we can only inject a further 250,000Mt into the atmosphere. At current emissions growth rates, this will take us about 20 years
If we are willing to accept a 50% chance of avoiding more than 2°C of warming, we can afford to emit an additional 250,000Mt — a total carbon budget of 1 trillion tonnes for all time
12 | NewScientist | 7 November 2009
What’s left
250,000 megatonnes of carbon 75% chance of staying below 2°C
250,000 megatonnes of carbon 50% chance of staying below 2°C
For daily news stories, visit www.NewScientist.com/news
A LOW-CARBON FUTURE STARTS HERE
By the time world leaders meet in Copenhagen in December, we will have emitted a further 824Mt of carbon
It’s being billed as the meeting that will determine the future of humanity. Come early December, we will be inundated with news from the Copenhagen summit. Can it really save us from climate catastrophe? Catherine Brahic and Fred Pearce sift through the mass of science and policy to pick out the key points to watch
TWO-hundred-and-fifty billion tonnes. That’s the bottom line. If we are serious about avoiding dangerous climate change, 250,000 megatonnes is the maximum amount of carbon we can put into the atmosphere. Keep going at current rates and we will have used up that ration in 20 years. The challenge for delegates at the week-long meeting in Denmark’s capital is to agree on ways of ensuring we do not exceed it – ever.
We are emitting nearly 10,000Mt of carbon each year. Unless we curb emissions we will exhaust the 250,000Mt budget by 2030
Why this year?
Two years ago in Bali, member nations of the UN Framework Convention on Climate Change (UNFCCC), which is convening the Copenhagen summit, agreed that they would accelerate their efforts and draft a long-term plan to avoid dangerous climate change. Their deadline for doing so is the close of this year’s summit, on 14 December. 20 10
Hasn’t the Kyoto protocol shown all this to be pointless? 20
20
Not necessarily. The Kyoto protocol was always intended as a first step. There are a number of differences this time around, most notably that the US opted out of the Kyoto protocol but is very much engaged in the Copenhagen process. 30
20
Why 250,000 megatonnes?
We have already emitted over 500,000 megatonnes of carbon – equivalent to about 1,800,000 megatonnes of carbon dioxide – mostly by burning
fossil fuels and cutting down forests. This year, climate scientists calculated that if we emit no more than 750,000 megatonnes in total, we will have a 75 per cent chance of limiting global warming to 2 °C.
What is the significance of 2 °C?
The objective of the UNFCCC is to prevent “dangerous” climate change. Although any amount of warming may have consequences – including biodiversity loss, changing weather patterns and disappearing coastlines – many climate scientists predict that some of those changes will be irreversible beyond 2 °C and others will pose a serious threat to millions of people. As a consequence, 2 °C has been adopted by politicians as the threshold for dangerous climate change.
Is 2 °C little enough?
That all depends: little enough for what? No amount of warming is risk-free, and modelling studies indicate that at 2 °C an additional 1 billion people will suffer water shortages and most of the world’s corals will be bleached. The world’s poorest nations, which include a number of island states that are particularly vulnerable to sea-level rise, are campaigning to limit warming to 1.5 °C. Given the effort that is going to be required to reach the 2 °C target, this is unlikely to be achieved. Moreover, lags in climate systems, plus the removal from the atmosphere of the fine aerosol particles now cooling the world, mean past emissions are likely to result in a 1.9 °C warming.
40
20 CUMULATIVE EMISSIONS: CDIAC-ORNL. CARBON BUDGETS: MEINSHAUSEN ET AL 2009, NATURE VOL 458, P 1158; ALLEN ET AL 2009, NATURE VOL 458, P 1163. EMISSIONS GROWTH RATES: CAIT-WRI. LAND USE EMISSIONS: HOUGHTON, PERSONAL COMMUNICATION 2009
7 November 2009 | NewScientist | 13
INSTANT EXPERT / COPENHAGEN
WHAT NEEDS TO BE DONE There are no two ways about it: to have any chance of avoiding the disastrous consequences of exceeding our carbon budget, we must usher in a new era of low-carbon societies. How this is done will depend on what deal can be reached between rich and developing nations. Both must agree to cut emissions according to their means and historical responsibility. Developing nations will also need money and technology to green their industrialisation. Where this will come from will be a key preoccupation for the Copenhagen negotiators
MONEY
THE HAVES...
It could cost the poorest nations hundreds of billions of dollars a year to curb their emissions and adapt to inevitable climate change. Rich nations are responsible for most of the gases that are already heating the planet, and have a duty to help foot this bill. Negotiators in Copenhagen will have to agree on how. Funds could be raised through taxes on emissions permits, for instance, or on international airline tickets. Or there could be a levy on all carbon emissions above certain national thresholds – as proposed by Switzerland. The European Union agreed last week to push for a fund worth €100 billion a year by 2020.
Cumulative tonnes of carbon emitted to 2006 To date, rich nations have emitted the lion’s share of carbon dioxide from burning fossil fuels, but developing nations are rapidly catching up. Sometime in the past three years, China became the world’s largest emitter of greenhouse gases, overtaking the US
DEVELOPING NATIONS OTHERS
DA
AUSTRALIA
R UN OPE IO AN N
228,800 million tonnes
US
IL
DEVELOPED NATIONS
CANA
CHINA
72,850 million tonnes
INDIA
14 | NewScientist | 7 November 2009
*relative to 1990 levels
AZ BR
Two billion people worldwide do not have access to mains electricity. To bridge that gap and power industry in developing countries, the International Energy Agency says $13 trillion must be invested in the developing world in the next 20 years. In Copenhagen, negotiators must seal a deal to ensure this goes mostly into low-carbon technologies – but how? Western engineering firms want an open door to developing markets, perhaps secured by a “green free trade” deal. Countries like India and China want deals with rich nations that would give their own companies free access to western know-how.
AGREED SO FAR
25-40% 80-95% 10-24% 40-80%
S ER
TECHNOLOGY
NEED
BY 2050
H OT
Around 15 per cent of emissions come from deforestation. WWF believes this could be cut by three-quarters by 2020, but that requires giving governments, landowners and forest communities incentives to stop destroying their forests. Two years ago, climate negotiators promised to sign such a deal – dubbed Reducing Emissions from Deforestation and Forest Degradation (REDD) – in Copenhagen. The cash could come from rich nations buying carbon offsets to meet their emissions targets. Brazil and Indonesia – which account for 60 per cent of emissions from deforestation – are keen. But close monitoring is essential to ensure loggers claiming cash for a forest do not continue chopping down individual trees or move their operations elsewhere. Also, countries such as Costa Rica that have protected their forests say it unfairly rewards those who got rich destroying theirs.
BY 2020
EU
FORESTS
must cut emissions* by:
For daily news stories, visit www.NewScientist.com/news
BUZZWORDS “Dangerous global warming” Avoiding this is the stated aim of the UN Framework Convention on Climate Change – although the convention did not say exactly what “dangerous” meant. Politicians have adopted 2 °C above pre-industrial temperatures as the threshold.
“Son of Kyoto”
...and
The deal agreed in Copenhagen is meant to be the Kyoto protocol’s successor, and so was at first popularly referred to as the “son of Kyoto”. In fact, the slow progress of negotiations means Copenhagen is unlikely to yield a new treaty. The Kyoto protocol sought to reduce emissions by 2012. Copenhagen will extend those efforts.
HAVE NOTS
must cut emissions* by:
“Adaptation”
BY 2020
The world is already committed to approximately a 1.9 °C temperature rise. Humans will have to learn to live with – or “adapt to” – this amount of unavoidable climate change.
15-30% 5-20%
NEED AGREED SO FAR
For the latest updates on reduction pledges, visit climateactiontracker.org
“Mitigation” Climate change jargon for the effort to cut greenhouse gas emissions.
*relative to business-as-usual development
Growth in CO2 emissions
DEAL BREAKERS
1100% India
900% 800%
Brazil
DEVELOPING NATIONS
700%
China 600% 500%
DEVELOPED NATIONS
400% 300% US
200%
EU 100%
20 05
95
20 00
90
19
19
85
75
80
19
19
70
19
65
19
19
60
0 19
Annual CO2 emissions relative to 1960
1000%
Who might thwart a deal? The US may not be able to make credible promises if Congress has not passed a climate change bill in time. If China and India think the US is not serious, they will hold back on pledges to green their own economic development. Others might wield a veto, too. Some newly industrialised countries – Malaysia and South Korea for instance – now have emissions higher than many European countries. They may protest if asked to sign up to firm targets. Malaysia’s emissions are four times what they were in 1990 and, per head of population, equal to the UK’s. Saudi Arabia’s emissions have doubled and, per head, now beat all European countries except Luxembourg. Qatar’s per-capita emissions are four times those of the US. Gulf states tried to torpedo Kyoto because they felt it threatened oil exports. Copenhagen could threaten their internal industrialisation plans. NEEDED EMISSIONS REDUCTIONS: IPCC AR4 WG3 BOX 13.7; DEN ELZEN ET AL, CLIMATIC CHANGE VOL 91, P 249. EMISSIONS REDUCTION PLEDGES*: WRI, CLIMATE ACTION TRACKER, ECOFYS AND CLIMATE ANALYTICS. DEFORESTATION EMISSIONS: HOUGHTON, PERSONAL COMMUNICATION, 2009. CUMULATIVE EMISSIONS: WRI-CAIT, CDIAC-ORNL. EMISSIONS GROWTH RATES: WRI-CAIT *SOME ASSUMPTIONS REGARDING NATIONAL POLICIES HAD TO BE MADE TO CALCULATE THESE RANGES
7 November 2009 | NewScientist | 15
GRAEME HARRIS/MILLENNIUM
Since 1960, CO2 emissions in rich nations have doubled while those in developing countries have grown sevenfold
What we’ve used
The world’s politicians and climate scientists have settled on 2 °C as the threshold for “dangerous” global warming. To stay below this we must emit no more than 750,000Mt of carbon in total. Sometime in 2006 we emitted the 500,000th megatonne
megatonnes of carbon
Deforestation 200,000Mt European Union 81,700Mt Since the beginning of the industrial revolution in the mid-1700s, humans have emitted over 500,000Mt of carbon. Roughly 200,000Mt has come from uprooting forests. The remainder is the result of burning fossil fuels and making cement, mostly in rich nations
US 91,200Mt
China 27,800Mt Canada 6800Mt Australia 3500Mt
Rest of world 66,000Mt
India 8300Mt
Africa 8200Mt
Latin America & Caribbean 12,500Mt Brazil 2600Mt
Climate scientists estimate that in order to have a 75% chance of avoiding more than 2°C of global warming we can only inject a further 250,000Mt into the atmosphere. At current emissions growth rates, this will take us about 20 years
If we are willing to accept a 50% chance of avoiding more than 2°C of warming, we can afford to emit an additional 250,000Mt — a total carbon budget of 1 trillion tonnes for all time
12 | NewScientist | 7 November 2009
What’s left
250,000 megatonnes of carbon 75% chance of staying below 2°C
250,000 megatonnes of carbon 50% chance of staying below 2°C
For daily news stories, visit www.NewScientist.com/news
A LOW-CARBON FUTURE STARTS HERE
By the time world leaders meet in Copenhagen in December, we will have emitted a further 824Mt of carbon
It’s being billed as the meeting that will determine the future of humanity. Come early December, we will be inundated with news from the Copenhagen summit. Can it really save us from climate catastrophe? Catherine Brahic and Fred Pearce sift through the mass of science and policy to pick out the key points to watch
TWO-hundred-and-fifty billion tonnes. That’s the bottom line. If we are serious about avoiding dangerous climate change, 250,000 megatonnes is the maximum amount of carbon we can put into the atmosphere. Keep going at current rates and we will have used up that ration in 20 years. The challenge for delegates at the week-long meeting in Denmark’s capital is to agree on ways of ensuring we do not exceed it – ever.
We are emitting nearly 10,000Mt of carbon each year. Unless we curb emissions we will exhaust the 250,000Mt budget by 2030
Why this year?
Two years ago in Bali, member nations of the UN Framework Convention on Climate Change (UNFCCC), which is convening the Copenhagen summit, agreed that they would accelerate their efforts and draft a long-term plan to avoid dangerous climate change. Their deadline for doing so is the close of this year’s summit, on 14 December. 20 10
Hasn’t the Kyoto protocol shown all this to be pointless? 20
20
Not necessarily. The Kyoto protocol was always intended as a first step. There are a number of differences this time around, most notably that the US opted out of the Kyoto protocol but is very much engaged in the Copenhagen process. 30
20
Why 250,000 megatonnes?
We have already emitted over 500,000 megatonnes of carbon – equivalent to about 1,800,000 megatonnes of carbon dioxide – mostly by burning
fossil fuels and cutting down forests. This year, climate scientists calculated that if we emit no more than 750,000 megatonnes in total, we will have a 75 per cent chance of limiting global warming to 2 °C.
What is the significance of 2 °C?
The objective of the UNFCCC is to prevent “dangerous” climate change. Although any amount of warming may have consequences – including biodiversity loss, changing weather patterns and disappearing coastlines – many climate scientists predict that some of those changes will be irreversible beyond 2 °C and others will pose a serious threat to millions of people. As a consequence, 2 °C has been adopted by politicians as the threshold for dangerous climate change.
Is 2 °C little enough?
That all depends: little enough for what? No amount of warming is risk-free, and modelling studies indicate that at 2 °C an additional 1 billion people will suffer water shortages and most of the world’s corals will be bleached. The world’s poorest nations, which include a number of island states that are particularly vulnerable to sea-level rise, are campaigning to limit warming to 1.5 °C. Given the effort that is going to be required to reach the 2 °C target, this is unlikely to be achieved. Moreover, lags in climate systems, plus the removal from the atmosphere of the fine aerosol particles now cooling the world, mean past emissions are likely to result in a 1.9 °C warming.
40
20 CUMULATIVE EMISSIONS: CDIAC-ORNL. CARBON BUDGETS: MEINSHAUSEN ET AL 2009, NATURE VOL 458, P 1158; ALLEN ET AL 2009, NATURE VOL 458, P 1163. EMISSIONS GROWTH RATES: CAIT-WRI. LAND USE EMISSIONS: HOUGHTON, PERSONAL COMMUNICATION 2009
7 November 2009 | NewScientist | 13
INSTANT EXPERT / COPENHAGEN
WHAT NEEDS TO BE DONE There are no two ways about it: to have any chance of avoiding the disastrous consequences of exceeding our carbon budget, we must usher in a new era of low-carbon societies. How this is done will depend on what deal can be reached between rich and developing nations. Both must agree to cut emissions according to their means and historical responsibility. Developing nations will also need money and technology to green their industrialisation. Where this will come from will be a key preoccupation for the Copenhagen negotiators
MONEY
THE HAVES...
It could cost the poorest nations hundreds of billions of dollars a year to curb their emissions and adapt to inevitable climate change. Rich nations are responsible for most of the gases that are already heating the planet, and have a duty to help foot this bill. Negotiators in Copenhagen will have to agree on how. Funds could be raised through taxes on emissions permits, for instance, or on international airline tickets. Or there could be a levy on all carbon emissions above certain national thresholds – as proposed by Switzerland. The European Union agreed last week to push for a fund worth €100 billion a year by 2020.
Cumulative tonnes of carbon emitted to 2006 To date, rich nations have emitted the lion’s share of carbon dioxide from burning fossil fuels, but developing nations are rapidly catching up. Sometime in the past three years, China became the world’s largest emitter of greenhouse gases, overtaking the US
DEVELOPING NATIONS OTHERS
DA
AUSTRALIA
R UN OPE IO AN N
228,800 million tonnes
US
IL
DEVELOPED NATIONS
CANA
CHINA
72,850 million tonnes
INDIA
14 | NewScientist | 7 November 2009
*relative to 1990 levels
AZ BR
Two billion people worldwide do not have access to mains electricity. To bridge that gap and power industry in developing countries, the International Energy Agency says $13 trillion must be invested in the developing world in the next 20 years. In Copenhagen, negotiators must seal a deal to ensure this goes mostly into low-carbon technologies – but how? Western engineering firms want an open door to developing markets, perhaps secured by a “green free trade” deal. Countries like India and China want deals with rich nations that would give their own companies free access to western know-how.
AGREED SO FAR
25-40% 80-95% 10-24% 40-80%
S ER
TECHNOLOGY
NEED
BY 2050
H OT
Around 15 per cent of emissions come from deforestation. WWF believes this could be cut by three-quarters by 2020, but that requires giving governments, landowners and forest communities incentives to stop destroying their forests. Two years ago, climate negotiators promised to sign such a deal – dubbed Reducing Emissions from Deforestation and Forest Degradation (REDD) – in Copenhagen. The cash could come from rich nations buying carbon offsets to meet their emissions targets. Brazil and Indonesia – which account for 60 per cent of emissions from deforestation – are keen. But close monitoring is essential to ensure loggers claiming cash for a forest do not continue chopping down individual trees or move their operations elsewhere. Also, countries such as Costa Rica that have protected their forests say it unfairly rewards those who got rich destroying theirs.
BY 2020
EU
FORESTS
must cut emissions* by:
For daily news stories, visit www.NewScientist.com/news
BUZZWORDS “Dangerous global warming” Avoiding this is the stated aim of the UN Framework Convention on Climate Change – although the convention did not say exactly what “dangerous” meant. Politicians have adopted 2 °C above pre-industrial temperatures as the threshold.
“Son of Kyoto”
...and
The deal agreed in Copenhagen is meant to be the Kyoto protocol’s successor, and so was at first popularly referred to as the “son of Kyoto”. In fact, the slow progress of negotiations means Copenhagen is unlikely to yield a new treaty. The Kyoto protocol sought to reduce emissions by 2012. Copenhagen will extend those efforts.
HAVE NOTS
must cut emissions* by:
“Adaptation”
BY 2020
The world is already committed to approximately a 1.9 °C temperature rise. Humans will have to learn to live with – or “adapt to” – this amount of unavoidable climate change.
15-30% 5-20%
NEED AGREED SO FAR
For the latest updates on reduction pledges, visit climateactiontracker.org
“Mitigation” Climate change jargon for the effort to cut greenhouse gas emissions.
*relative to business-as-usual development
Growth in CO2 emissions
DEAL BREAKERS
1100% India
900% 800%
Brazil
DEVELOPING NATIONS
700%
China 600% 500%
DEVELOPED NATIONS
400% 300% US
200%
EU 100%
20 05
95
20 00
90
19
19
85
75
80
19
19
70
19
65
19
19
60
0 19
Annual CO2 emissions relative to 1960
1000%
Who might thwart a deal? The US may not be able to make credible promises if Congress has not passed a climate change bill in time. If China and India think the US is not serious, they will hold back on pledges to green their own economic development. Others might wield a veto, too. Some newly industrialised countries – Malaysia and South Korea for instance – now have emissions higher than many European countries. They may protest if asked to sign up to firm targets. Malaysia’s emissions are four times what they were in 1990 and, per head of population, equal to the UK’s. Saudi Arabia’s emissions have doubled and, per head, now beat all European countries except Luxembourg. Qatar’s per-capita emissions are four times those of the US. Gulf states tried to torpedo Kyoto because they felt it threatened oil exports. Copenhagen could threaten their internal industrialisation plans. NEEDED EMISSIONS REDUCTIONS: IPCC AR4 WG3 BOX 13.7; DEN ELZEN ET AL, CLIMATIC CHANGE VOL 91, P 249. EMISSIONS REDUCTION PLEDGES*: WRI, CLIMATE ACTION TRACKER, ECOFYS AND CLIMATE ANALYTICS. DEFORESTATION EMISSIONS: HOUGHTON, PERSONAL COMMUNICATION, 2009. CUMULATIVE EMISSIONS: WRI-CAIT, CDIAC-ORNL. EMISSIONS GROWTH RATES: WRI-CAIT *SOME ASSUMPTIONS REGARDING NATIONAL POLICIES HAD TO BE MADE TO CALCULATE THESE RANGES
7 November 2009 | NewScientist | 15
GRAEME HARRIS/MILLENNIUM
Since 1960, CO2 emissions in rich nations have doubled while those in developing countries have grown sevenfold