Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as global warming.
Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record—extending deep into the Earth's past—has been assembled, and continues to be built up, based on geological evidence from borehole temperature profiles, cores removed from deep accumulations of ice, floral and faunal records, glacial and periglacial processes, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.
This topic looks at evidence of climate change, contributing factors, initiatives to limit climate change and opinions on climate change.
ATLANTA - Climate change is poised to affect the world's food supply in three key ways, experts say. "There will be impacts on the quantity, quality and location of the food we produce," said Dr. Sam Myers, a medical doctor and senior research scientist studying environmental health at the Harvard T.H.
Unless by some miracle almost every climate scientist is wrong, future generations will look upon ours with puzzlement and anger - as the people who might have prevented the Earth from becoming a habitat unfriendly to humans and other species but nonetheless failed to act.
Published in the journal Climate Risk Management today, our research is the first to quantify the probability of historical changes in global temperatures and examines the links to greenhouse gas emissions using rigorous statistical techniques. Our new CSIRO work provides an objective assessment linking global temperature increases to human activity, which points to a close to certain probability exceeding 99.999%.
Climate change is no longer a niche political issue. Recent events such as the drought in California and Superstorm Sandy have brought extreme weather to the forefront, and people are searching for information on climate and weather connections. Voters, reporters and debate moderators are increasingly asking questions about climate change.
This page answers some of the most commonly asked questions about climate change and its impacts. Click on the questions below to view the answers. Is there a scientific consensus on climate change? Yes.
Climate models have proven extremely skillful in predicting the warming that has already been observed...
It am Michael Mann, saying Climate models have proven extremely skillful in predicting the warming that has already been observed and, by many measures (e.g. Arctic sea ice loss, melting of the major ice sheets) it is proceeding faster than climate models predicted... Notice any problems with that quote?