Let’s Talk About Climate Change

climate change

Many questions surround climate change and its effects. One question that has a clear answer: climate change is real. (Photo credit: ALAN DAWSON PHOTOGRAPHY/Alamy Images)

What is climate change? What evidence supports climate change? What role do humans play in climate change? Read on to find the answers to these questions and a few other frequently-asked questions about this topic.

What is the difference between global warming and climate change?
Global warming refers to the long-term warming of Earth. There is well-documented evidence that global temperatures have been on the increase since the early 20th century. Global temperatures have increased even more significantly since the late 1970s. According to climate research, since 1880, the average surface temperature of Earth has increased by 0.8°C (or 1.4°F). The term climate change incorporates global warming as well as a wider range of changes on Earth, including rising sea levels, melting glaciers, accelerating ice melt, and changes in plant budding patterns and animal migrations.

What is the evidence that supports climate change?
There are a number of pieces of evidence that support climate change. These include:

  • Declining Arctic Ice Research indicates that the thickness of Arctic sea ice has decreased quickly over the last several decades.
  • Decreased Snow Cover According to the National Snow and Ice Data Center, over the past 50 year, the amount of snow cover in the Northern Hemisphere has decreased and snow is melting earlier in the year as well.
  • Extreme Weather Events The number of extreme weather events, such as hurricanes, typhoons, and other severe storms, has increased in rate of occurrence and intensity.
  • Glacial Retreat In mountain ranges around the world, glaciers are melting and declining in size, if not disappearing completely.
  • Global Temperature Rise According to NOAA, overall, the global annual temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880 and at an average rate of 0.17°C (0.31°F) per decade since 1970. Data indicates that 2016 was the hottest year on record, and the third consecutive temperature record-breaking year.
  • Ocean Acidification An increase in CO2 emissions has led to an increase in ocean acidification. Scientists expect ocean acidification to have ramifications throughout oceanic food webs.
  • Sea Level Rise According to research published in Geophysical Research Letters, global sea level rose about 17 centimeters (6.7 inches) in the last century.
  • Shrinking Ice Sheets An ice sheet is a glacial land ice mass that extends more than 50,000 square kilometers (20,000 square miles). The Antarctic and Greenland ice sheets contain over 99 percent of Earth’s freshwater ice. These ice sheets are both decreasing in size. Research published in Geophysical Research Letters using satellite data showed that Greenland lost a trillion tons of ice between 2011 and 2014.
  • Warming Oceans According to research published in Geophysical Research Letters, the top 700 meters (2300 feet) of ocean have warmed 0.302 °F over the past 50 years.

Where does the data come from?
Climate researchers use direct and indirect measurements, including satellite observations and glacial ice samples. Modern climate data is gathered from weather stations, weather balloons, radars, satellites, and moored and drifting buoys (which gather sea temperature data). Climate scientists also rely on historical texts, such as logbooks from explorers, to gather data on climate conditions from the past.

Do scientists agree about climate change?
The vast majority–over 97 percent–of scientists agree without a doubt that human activities are causing global warming and climate change. The majority of leading scientific organizations, including U.S. and international science academies, the UN Intergovernmental Panel on Climate Change, and other scientific bodies have all issued statements in support of this conclusion.

More to Explore
National Climate Assessment
Global Climate Change
Earth Sets a Temperature Record for the Third Straight Year
National Snow & Ice Data Center
Greenland is Melting

What Do You Think?

*