The Basics of Global Warming
We've put together these basic frequently asked questions to give you a starting point in your global warming education. When you're done reading up on the basics, check out our solutions page to learn more about how you can curb global warming.
What causes global warming? Is it part of a natural cycle?
Global warming is caused by the build up of greenhouse gases in the atmosphere such as carbon dioxide and methane, which form a sort of blanket over the Earth, trapping in heat that would normally escape the atmosphere. The leading greenhouse gas is carbon dioxide, a pollutant emitted from the burning of fossil fuels, such as coal, oil, and natural gas. While it is true that there has always been some natural climate variability, record levels of carbon dioxide are having a far reaching change over our weather, sea levels, and climate.
Throughout ice ages, higher concentrations of carbon dioxide have correlated with higher temperatures. Humans are exacerbating global temperatures through industrial activity which dramatically increases carbon dioxide concentrations in the atmosphere. In its recent report, the Intergovernmental Panel on Climate Change found that 2005 carbon dioxide levels significantly exceed average concentration levels over the past 650,000 years.
Click here to read the report on global warming science by the Intergovernmental Panel on Climate Change, the world's leading scientific body on global warming.
How can Global Warming affect our lives?
We do not yet fully know how radical climate change will affect our way of life, but we do know that the effects of growing carbon dioxide emissions already occurring are staggering: the eleven years ranging between 1995 and 2006 rank among the twelve warmest years recorded since 1850. Sea level rise will likely increase 20-50 inches (.5-1.4 m) above 1990 levels by 2100, dramatically altering coastal communities and natural habitats.
Leading scientists assert that a rise of 2º C over pre-industrial temperatures would leave hundreds of millions of people around the world "exposed to increased water stress," decrease air quality in cities, increase ocean acidification leading to the destruction of calcifying marine life (including coral and dependent species), negatively impact farmers and fishers, increase the likelihood and severity of wildfires, and dramatically escalate mortality rates resulting from drought, floods, and heat waves. Few ecosystems could adapt to such a dramatic temperature change, potentially resulting in the extinction of 30% of species and the loss of 30% of coastal wetlands. In North America specifically, higher temperatures will decrease snow pack in the western mountains, reducing summer water supplies and exacerbating chances of drought.
To avoid such catastrophes, scientists say that we must reduce our carbon emissions by at least 80% by 2050 to prevent global temperatures from rising above 2º C over pre-industrial averages.
Read the IPCC's definitive report on the possible impacts of global warming.
