CLIMATE CHANGE SCIENCE
Antonio J. Busalacchi, Jr., Ph.D.
Chairman, Climate Research Committee
National Academy of Sciences
Director, Earth System Science Interdisciplinary Center (ESSIC),
University of Maryland
COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION
OCTOBER 1, 2003
Good morning. Thank you very much for this opportunity to testify. I am Dr. Tony Busalacchi, a professor at the University of Maryland and I serve as the chair of The National Academies’ Climate Research Committee. I will use my time this morning to summarize what most scientists agree to be true about change in the Earth’s climate.
Understanding climate and whether it is changing, and why, is one of the most crucial questions facing humankind in the twenty-first century. This question is the subject of much scientific research and, of course, policy debate, since the economic and environmental implications could be large. The National Academies have produced a number of reports focused on understanding climate in recent years and my testimony draws heavily from two of these: a February 2003 report that gives input to the Administration’s draft US Climate Change Science Program Strategic Plan (NRC 2003) and a 2001 report called “Climate Change Science” that was done at the request of the White House (NRC 2001). The latter report answered a series of specific questions designed to identify areas in climate change science where there are the greatest certainties and uncertainties. If you haven’t read this report, it is an excellent summary (only 25 pages long) written in very accessible language.
As is explained in “Climate Change Science,” there is wide scientific consensus that climate is indeed changing. Greenhouse gases are accumulating in Earth’s atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Our confidence in this conclusion is higher today than it was ten, or even five years ago, but uncertainty remains because there is a level of natural variability inherent in the climate system on time scales of decades to centuries that can be difficult to interpret with precision because we gather this evidence from sparse observations, numerical models, and proxy records such as ice cores and tree rings. Despite the uncertainties, however, there is widespread agreement that the observed warming is real and particularly strong within the past twenty years.
Yes, I do agree with the climate scientists. Not just because they’re the most knowledgeable people on the planet about this subject, but also because they put their evidence out there for the whole world to examine.
The scientific evidence overwhelmingly shows that humans are the primary cause of the current global warming. To argue otherwise at this point is simply to remain in denial.
on: 25th September 07