Climate Change is a term used to describe global changes in weather and temperature caused by human activities. While Earth’s climate has always changed, the rate of global warming is currently accelerating. Climate Change is already causing the melting of snow and ice, rising sea levels, shifting rainfall patterns, changing animal and plant geographic ranges, and more frequent and intense heat waves.
While we can’t say exactly how much the world will warm in the future, we know that we need to significantly reduce our emissions of heat-trapping gases like carbon dioxide and methane in order to avoid a worsening of these effects. This is a task that will require the efforts of all countries and all communities, but it’s particularly important for wealthy nations, such as the United States, to lead the way.
Global average temperatures have been rising since the beginning of the industrial era, and it’s clear that human activity has contributed to this. Scientists estimate that the world could warm by as much as eight feet by century’s end if we don’t substantially reduce our emissions. This would put millions of people at risk for coastal flooding, and it would also increase the likelihood that low-lying island nations will disappear.
There have been times in Earth’s history when the global temperature has been warmer than it is now, but we have never before seen such a large amount of warmth trapped in the atmosphere for so long a period of time. Many of the changes that scientists have predicted—such as accelerated glacier and ice sheet melt, sea level rise, and severe weather events—are happening now and are more rapid than expected.
The recent Intergovernmental Panel on Climate Change (IPCC) Special Report has made it clear that avoiding the most dangerous impacts of climate change will require “rapid and far-reaching” transformations in land, energy, buildings, transportation, and industry. This will require cutting global net human-caused emissions to zero by 2050, with no fossil fuels remaining in the ground or in the air.
There is no time to waste. The impacts of climate change are already being felt everywhere: from straining food supplies to more intense hurricanes and wildfires, from increased air pollution to more mosquito-borne diseases. The IPCC’s report shows that even the best-off nations will be hard-pressed to cope with these changes, and that those living in the poorest places will be hardest hit. They will be least able to adapt, and their health will be harmed by extreme heat, reduced food production, lack of clean water, displacement, malnutrition, and stress. The report is a comprehensive assessment of the science behind these impacts, involving thousands of scientists and extensive review and public input. It is the most thorough, transparent scientific assessment of climate change ever produced.