INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
Climate Change 2007: The Physical Science Basis Summary for Policymakers
Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
This Summary for Policymakers was formally approved at the 10th Session of Working Group I of the IPCC, Paris, February 2007.
The Working Group I contribution to the IPCC Fourth Assessment Report describes progress in understanding of the human and natural drivers of climate change, observed climate change, climate processes and attribution, and estimates of projected future climate change.
(translation: The group of scientists who wrote this part of the report were responsible for assessing which event was triggered by what and whether it will happen again)
It builds upon past IPCC assessments and incorporates new findings from the past six years of research. Scientific progress since the TAR is based upon large amounts of new and more comprehensive data, more sophisticated analyses of
data, improvements in understanding of processes and their simulation in models, and more extensive exploration of uncertainty ranges.
(translation: We put together everything from the last 6 years to create this report)
(image upper right from Beijing Climate Center of: Academician Qin Dahe, Administrator of CMA, Co-Chairman of IPCC Working Group 1 leading the Chinese delegation )
HUMAN AND NATURAL DRIVERS OF CLIMATE CHANGE
Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice cores spanning many thousands of years.
(translation: Pollution levels are now higher than they've been in thousands of years)
The global increases in carbon dioxide concentration are due primarily to fossil fuel use and land-use change, while those of methane and nitrous oxide are primarily due to agriculture.
(translation: Between burning fossil fuels, torching the rainforests, and agriculture, we've managed to get ourselves into a bit of a pickle)
The global atmospheric concentration of methane has increased from a pre-industrial value of about 715 ppb to 1732 ppb in the early 1990s, and is 1774 ppb in 2005.
The atmospheric concentration of methane in 2005 exceeds by far the natural range of the last 650,000 years (320 to 790 ppb) as determined from ice
(translation: There is one heck of a lot of cow dung showing up on the readings; more than we've seen in 650K years in fact)
The global atmospheric nitrous oxide concentration increased from a pre-industrial value of about 270 ppb to 319 ppb in 2005.
The growth rate has been approximately constant since 1980. More than a third of all nitrous oxide emissions are anthropogenic and are primarily due to agriculture.
The understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming,(translation: Yep, it's getting warmer!)