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Ditch the hygiene for a healthy heart
THIS WEEK INSIGHT Why there’s no sign of a climate conspiracy in hacked emails Many are claiming that the material obtained from the Climate Research Unit (CRU) at the University of East Anglia, UK, proves human-made global warming is a conspiracy. It doesn’t.
You can’t fake spring coming earlier, or trees growing higher up the sides of mountains, or glaciers retreating, or Arctic ice disappearing, or Alaskan permafrost melting, or the tropics expanding, or ice shelves breaking up, or sea levels rising faster and faster. There are thousands of similar examples from around the world. None of these observations by themselves prove the world is warming. But put all the data together, and you have overwhelming evidence of a long-term warming trend – even without the temperature records compiled by researchers.
Ditch the hygiene for a healthy heart AFFLUENT, modern babies live in a sanitised world. This has already been blamed for a high incidence of asthma and allergies, but might also up the risk of developing a host of other conditions common in rich countries, such as stroke and heart disease. According to the “hygiene hypothesis”, our immune system evolved to handle a germ-laden world. If we don’t encounter many pathogens during infancy, it doesn’t learn to keep itself in check, and turns on 16 | NewScientist | 12 December 2009
So why are scientists “fixing” temperature data?
Surely the researchers’ attempts to block publication of sceptical scientific papers are indefensible?
What about the attempts to avoid freedom of information requests?
Raw data almost always has to be manipulated to correct for problems with the way measurements were made, or to reconcile measurements
We should wait for the independent inquiry to determine if there was any wrongdoing. The emails suggest some of the scientists may have tried to shut
The truth can be a powerful weapon
JULIAN MAKEY/REX FEATURES
The physics is clear: carbon dioxide is a greenhouse gas, greenhouse gases warm the atmosphere, and CO2 is accumulating in the atmosphere.
out critics, which, if true, goes against advancing knowledge through open debate. On the other hand, the aim of peer review is to prevent substandard research from being published, so you could argue that the scientists were just doing their job because they felt the papers in question were not scientifically rigorous.
Other explanations have been ruled out, using a combination of modelling studies and observation. Direct measurements since the 1970s prove the recent warming is not due to changes in solar activity, for instance.
How can we be sure the world really is warming?
How do we know greenhouse gases are the main cause?
made in different ways. Some apparent problems with model forecasts, for example, have turned out to be due to the failure to correct for the gradual changes in satellite orbits. The question is where to draw the line. It remains to be seen if any adjustment referred to in the emails cannot be justified.
inflammation – normally a response to infection – in inappropriate situations. This reaction, the hypothesis goes, is responsible for the recent increase in asthma and allergies, both associated with inflammation. Recently, it has emerged that chronic inflammation may also increase the risk of diabetes, stroke and heart diseases. So might the hygiene hypothesis be implicated here too? To find out, Tom McDade of Northwestern University in Evanston, Illinois, and colleagues turned to health surveys, which began at birth, of 1534 children in Cebu City in the Philippines, where western levels of sanitation are generally not found. When these people reached 20,
McDade’s team were able to test their blood for C-reactive protein (CRP), a marker of chronic inflammation. They found that the more pathogens the people had encountered before age 2, the less CRP they had at age 20. Every episode of diarrhoea back then cut the chance of higher CRP later by 11 per cent; every two months spent in a place with animal faeces cut it by 13 per cent. Being born in the dusty, dirty dry season cut the chance by a third (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2009.1795).
“Every episode of diarrhoea as an infant cut the chance of high adult levels of an inflammatory protein”
While we don’t have the full facts, on the surface it does appear that Phil Jones, the director of the CRU who has temporarily stepped down while an inquiry is carried out, discussed deleting some emails to avoid disclosing them. Whether the researchers broke any laws or breached any university guidelines will be determined by the CRU’s independent inquiry. In other cases, however, it is clear that researchers could not comply with freedom of information requests because they did not have the right to release all the data in question. The CRU received more than 50 such requests in one week alone this year, and the researchers feel that climate-change deniers were using such requests to harass them and waste their time. Michael Le Page and Catherine Brahic ■
McDade suggests that early exposure to germs could reduce chronic inflammation later in life, and therefore the risk of developing a host of serious conditions. “This takes the hygiene hypothesis well beyond allergy,” he says. “This is consistent with the effect of germs on immune development,” says Richard Gallo of the University of California, San Diego. McDade hopes that one day we may be able to safely expose babies to the protective elements of germs without incurring the risks that come with infections. In the meantime, he is taking a less high-tech approach: “If my 2-year-old drops food on the floor, I just let him pick it up and eat it.” Debora MacKenzie ■
You can’t fake spring coming earlier, or trees growing higher up the sides of mountains, or glaciers retreating, or Arctic ice disappearing, or Alaskan permafrost melting, or the tropics expanding, or ice shelves breaking up, or sea levels rising faster and faster. There are thousands of similar examples from around the world. None of these observations by themselves prove the world is warming. But put all the data together, and you have overwhelming evidence of a long-term warming trend – even without the temperature records compiled by researchers.
Ditch the hygiene for a healthy heart AFFLUENT, modern babies live in a sanitised world. This has already been blamed for a high incidence of asthma and allergies, but might also up the risk of developing a host of other conditions common in rich countries, such as stroke and heart disease. According to the “hygiene hypothesis”, our immune system evolved to handle a germ-laden world. If we don’t encounter many pathogens during infancy, it doesn’t learn to keep itself in check, and turns on 16 | NewScientist | 12 December 2009
So why are scientists “fixing” temperature data?
Surely the researchers’ attempts to block publication of sceptical scientific papers are indefensible?
What about the attempts to avoid freedom of information requests?
Raw data almost always has to be manipulated to correct for problems with the way measurements were made, or to reconcile measurements
We should wait for the independent inquiry to determine if there was any wrongdoing. The emails suggest some of the scientists may have tried to shut
The truth can be a powerful weapon
JULIAN MAKEY/REX FEATURES
The physics is clear: carbon dioxide is a greenhouse gas, greenhouse gases warm the atmosphere, and CO2 is accumulating in the atmosphere.
out critics, which, if true, goes against advancing knowledge through open debate. On the other hand, the aim of peer review is to prevent substandard research from being published, so you could argue that the scientists were just doing their job because they felt the papers in question were not scientifically rigorous.
Other explanations have been ruled out, using a combination of modelling studies and observation. Direct measurements since the 1970s prove the recent warming is not due to changes in solar activity, for instance.
How can we be sure the world really is warming?
How do we know greenhouse gases are the main cause?
made in different ways. Some apparent problems with model forecasts, for example, have turned out to be due to the failure to correct for the gradual changes in satellite orbits. The question is where to draw the line. It remains to be seen if any adjustment referred to in the emails cannot be justified.
inflammation – normally a response to infection – in inappropriate situations. This reaction, the hypothesis goes, is responsible for the recent increase in asthma and allergies, both associated with inflammation. Recently, it has emerged that chronic inflammation may also increase the risk of diabetes, stroke and heart diseases. So might the hygiene hypothesis be implicated here too? To find out, Tom McDade of Northwestern University in Evanston, Illinois, and colleagues turned to health surveys, which began at birth, of 1534 children in Cebu City in the Philippines, where western levels of sanitation are generally not found. When these people reached 20,
McDade’s team were able to test their blood for C-reactive protein (CRP), a marker of chronic inflammation. They found that the more pathogens the people had encountered before age 2, the less CRP they had at age 20. Every episode of diarrhoea back then cut the chance of higher CRP later by 11 per cent; every two months spent in a place with animal faeces cut it by 13 per cent. Being born in the dusty, dirty dry season cut the chance by a third (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2009.1795).
“Every episode of diarrhoea as an infant cut the chance of high adult levels of an inflammatory protein”
While we don’t have the full facts, on the surface it does appear that Phil Jones, the director of the CRU who has temporarily stepped down while an inquiry is carried out, discussed deleting some emails to avoid disclosing them. Whether the researchers broke any laws or breached any university guidelines will be determined by the CRU’s independent inquiry. In other cases, however, it is clear that researchers could not comply with freedom of information requests because they did not have the right to release all the data in question. The CRU received more than 50 such requests in one week alone this year, and the researchers feel that climate-change deniers were using such requests to harass them and waste their time. Michael Le Page and Catherine Brahic ■
McDade suggests that early exposure to germs could reduce chronic inflammation later in life, and therefore the risk of developing a host of serious conditions. “This takes the hygiene hypothesis well beyond allergy,” he says. “This is consistent with the effect of germs on immune development,” says Richard Gallo of the University of California, San Diego. McDade hopes that one day we may be able to safely expose babies to the protective elements of germs without incurring the risks that come with infections. In the meantime, he is taking a less high-tech approach: “If my 2-year-old drops food on the floor, I just let him pick it up and eat it.” Debora MacKenzie ■