The bulk of global warming, say the IPCC scientists, as well as the resulting havoc wreaked on the world's ecosystems, can be blamed on human activity. Smoke billows from the Exxon oil refinery near Baton Rouge, Louisiana. A Changing Home Carbon dioxide is an essential component of Earth's atmosphere. But since 1750, the gas's concentration has increased by 31 percent, the IPCC scientists note, reaching levels likely not exceeded in the past 20 million years. An increased amount of greenhouse gases, including carbon dioxide, trap heat in the atmosphere, upping the Earth's average surface air temperature.
Scientists blame a myriad of effects on the Earth's land, water, and air on the temperature change.
According to the IPCC report, snow cover decreased ten percent since the late 1960s. The scientists also blame changing weather patterns on global warming. Each of these meteorological effects has the potential to dramatically affect life on Earth. Land-dwelling animals, he added, will also be threatened, and may not be able to migrate fast enough to escape weather changes. Humans, named as the primary cause of global warming, are not immune to its effects.