Human influence
Using basic physics, observational data and computational models, scientists have determined that recent climate change is the result of human activity. Human activity—especially the burning of fossil fuels—has increased atmospheric concentrations of heat-trapping gases like carbon dioxide. This intensifies the Earth’s naturally warming greenhouse effect.
Global temperatures are influenced by natural forces and human activities. Data show that temperature trends since about 1960 have been highly influenced by humans. Graphic adapted from from Bloomberg’s What’s Really Warming the World.
What does the evidence look like?
Extra heat in the atmosphere is changing our climate, and the evidence is compelling. The planet’s average surface temperature is rising; oceans are warming and becoming more acidic; Arctic sea ice is declining; sea level is rising; and extreme events such as record high temperatures and intense rainfall are happening more frequently in all regions of the world. Furthermore, present levels of atmospheric CO2 and other greenhouse gases in the atmosphere are unprecedented in the past million years, and the speed of the current climate change is also faster than past changes.
Credit: NASA’s Scientific Visualization Studio/Cindy Starr.
Decades of research have provided a good understanding of the basic links between human activities, greenhouse gas emissions, changes in the atmosphere, the response of the physical climate system and the impacts on human and natural systems.
More detailed aspects of the problem remain active research areas at Purdue, such as climate sensitivity, impact projections as well as how individuals, cities and the international community are responding to climate change.
