IPCC Scientist Says Climate Change Likely to Accelerate More Quickly and Be More Damaging Than Predicted
Without decisive action, climate change this century is likely to accelerate at a much faster pace and cause more environmental damage than predicted, according to Professor Chris Field of Stanford University, and a leading member of the UN Intergovernmental Panel on Climate Change.
There is a real risk that human-caused climate change will accelerate the release of carbon dioxide from forest and tundra ecosystems, which have been storing a lot of carbon for thousands of years. We don’t want to cross a critical threshold where this massive release of carbon starts to run on autopilot.—Chris Field
Field gave his presentation, entitled “Carbon-Climate System and the Terrestrial Biosphere” at the annual meeting of the American Association for the Advancement of Science (AAAS) in Chicago during a symposium titled, “What Is New and Surprising Since the IPCC Fourth Assessment?”
We now have data showing that from 2000 to 2007, greenhouse gas emissions increased far more rapidly than we expected, primarily because developing countries, like China and India, saw a huge upsurge in electric power generation, almost all of it based on coal. If we’re going to continue re-carbonizing the energy system, we’re going to have big CO2 emissions in the future. As a result, the impacts of climate change will probably be more serious and diverse than those described in the fourth assessment.
In the fourth assessment, we looked at a very conservative range of climate outcomes. The fifth assessment should include futures with a lot more warming.—Chris Field
Of particular concern is the impact of global warming on the tropics. Tropical forests are essentially inflammable, according to Field, but if they dry out just a little bit, the result can be very large and destructive wildfires.
According to several recent climate models, loss of tropical forests to wildfires, deforestation and other causes could increase atmospheric CO2 concentrations from 10 to 100 parts per million (ppm) by the end of the century. This would be a significant relative increase, given that the total concentration of CO2 in the atmosphere is currently more than 385 ppm.
It is increasingly clear that as you produce a warmer world, lots of forested areas that had been acting as carbon sinks could be converted to carbon sources. Essentially we could see a forest-carbon feedback that acts like a foot on the accelerator pedal for atmospheric CO2. We don’t exactly know how strong the feedback could be, but it’s pretty clear that the warmer it gets, the more likely it is that degradation of tropical forests will increase the atmospheric CO2.—Chris Field
For the fifth assessment report, Field said that he and his IPCC colleagues will have access to new research that will allow them to do a better job of assessing the full range of possible climate outcomes.
What have we learned since the fourth assessment? We now know that, without effective action, climate change is going to be larger and more difficult to deal with than we thought. If you look at the set of things that we can do as a society, taking aggressive action on climate seems like one that has the best possibility of a win-win. It can stimulate the economy, allow us to address critical environmental problems, and insure that we leave a sustainable world for our children and grandchildren. Somehow we have to find a way to kick the process into high gear. We really have very little time.—Chris Field