According to NASA, the American space agency that also monitors global surface temperatures, 2012 was the 9th warmest year recorded since 1880. The average temperature for 2012 was 0.6°C (1.0°F) higher than the annual average temperature (14.00°C/57.2°F) for the years 1951 to 1980, an average that is often used for comparison purposes.
The 10 warmest years that have ever been recorded have all occurred since 1998. The hottest years have been 2005 and 2010. The warmer temperatures last year also impacted the Arctic sea ice. The Arctic sea ice cover on September 16 was the lowest that has ever been recorded. The Arctic sea ice floats in the water body around the North Pole region. The ice cover melts and decreases in the summer months, and refreezes and increases in the winter months. The rate of Arctic sea ice loss in August was 91,700 sq km (35,400 sq miles) per day. That’s about the size of Portugal lost every day! This is the fastest rate ever observed. The Arctic sea ice is very important. It acts like our planet’s air conditioner and helps control Earth’s climate.
Earth’s average global temperature has increased by about 0.8°C (1.4°F ) over the last 132 years. Many scientists believe that the Earth has gotten warmer because of an increase in greenhouse gases created by some of our activities. Carbon dioxide and a few other gases such as methane, ozone, and nitrous oxide are called greenhouse gases because they help create something called “the greenhouse effect”. This is what keeps the Earth warm – without these gases, our planet would have been much colder. However, human activity has now driven up the production of these greenhouse gases. For example, when our car runs on petrol, it is producing carbon dioxide. When our computer runs at home, it needs electricity, which we get from a power plant. Many of the power plants burn fossil fuels, and that in turn produces more carbon dioxide. For comparison purposes, the carbon dioxide level in the atmosphere was about 285 parts per million in 1880 and now is over 390 parts per million. The larger amount of greenhouse gases is making our planet warmer than its usual state, causing global warming.
Here are a couple of videos about the greenhouse effect and how temperatures have changed since 1880.
Did you know? Recently, NASA used laser technology to beam over one of the world’s most famous paintings to the Lunar Reconnaissance Orbiter (LRO), a spacecraft orbiting our moon. Leonardo da Vinci’s Mona Lisa traveled nearly 240,000 miles (385,000 km) through space to reach the LRO.
Image Credits: NASA for temperature image; NSIDC for Arctic sea ice image