But, how do we know this is right?

While many reporters cover climate issues - like this one taking notes during a demonstration for the enforcement of Kyoto Protocol - some of them only confuse the issue. Credit: ItzaFineDay

Be careful – the people you trust may be leading you astray. Are they worthy of your faith in them? Does what they say really represent reality?

These may sound like strange ramblings, but if we all answered truthfully we might better understand the major causes of the current debate on climate change. Everyone in the world depends on their own set of sources of information. We share many of them, like television programs and newspapers, with others. We also have some sources that others don’t, like our friends, or maybe an obscure little website. But, as Australian psychologist Ben Newell and climate change researcher Andrew Pitman warned earlier this month, we often don’t realise when these sources are biased.

Worse still, the University of New South Wales researchers note that we tend to select evidence that supports opinions we already hold. “Misinformation, the occasional cold day, and the misquoting of science allow a large fraction of the public and policy makers to retain their existing mental models,” they wrote in the Bulletin of the Meteorological Society. Consequently, it is relatively easy for us to ignore clear scientific evidence. Yet, according to what Beijing Normal University’s John Moore told Simple Climate earlier this month, there is clear evidence. “Sea level rise over the last 200 years is measured,” he said. “It’s the highest we have seen.” And, as Stanford University’s George Somero noted: “There is no longer any doubt about the rate of global warming or the role of [man-made] greenhouse gases in this on-going process.”

The ratio of record daily temperature highs to record daily lows observed at about 1,800 weather stations in the 48 main United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now standing at about two-to-one for the 48 states as a whole. Credit: UCAR, graphic by Mike Shibao

Somero and Moore are two of 10 researchers that have helped this blog try and directly answer climate change questions since July, keeping bias to a minimum, taking the total so far this year to 26. Unlike the media, researchers themselves try and eliminate excessive bias, by letting independent, typically anonymous, scientists scrutinise their work before publication, in a process called peer review. “The fact that your research is constantly being evaluated by the community and that promotion at universities depends on people’s assessment of the quality of your work ensures that blatant distortions are rare and/or go unrewarded,” explained the University of British Columbia’s Simon Donner.

Given the opportunity to address a less specialised audience here, the scientists shared dramatic predictions arising from their work. For example, Bob Kopp suggested that if we don’t change our ways “then by the end of the century CO2 levels will probably be about as high as they have been in about 40 million years”. Kopp, a science and technology policy fellow at the American Association for the Advancement of Science, emphasises that 40 million years ago, temperatures were “5-10ºC warmer than today and there weren’t permanent ice sheets”.

Jens Borken-Kleefeld of Austria’s International Institute for Applied Systems Analysis, pointed out that the speed of climate change is also a concern. “We could trigger some irreversible events, like switching off the Gulf Stream, or melting of the Arctic, which is as much linked to the level but more to the rate of change.” Meanwhile, Penn State University’s Nick Polato predicted drastic declines in the number and diversity of coral reefs, his specific area of expertise.

The last three months have also seen some inventive answers to the challenge that is the purpose of this blog, namely to provide a simple explanation of climate change. Columbia University’s Shahzeen Attari chose a diagram to show how human greenhouse gas emissions affect natural cycles, and then explained the link between those cycles and climate change. Carnegie Insitution of Washington’s Steven Davis compared the Earth to a car parked in the sun. He said:

“The earth is the car, and the car’s windows are CO2. Humans evolved on a planet with relatively low CO2 – the windows a good way down and a nice breeze blowing through. But every molecule of CO2 we put in the atmosphere inches the windows up, and the car is heating up uncomfortably.”

However, sadly, even though peer review helps make their research findings more reliable, scientists don’t have all the answers. That much was shown when University of Georgia’s Wei-Jun Cai and Boris Worm from Dalhousie University, Canada, attempted to answer a reader’s question. Whether or not the fall in phytoplankton caused by climate change that Worm documented will reduce overall production of oxygen “is quite unclear,” he said.