Global warming is an increase in ordinary temperatures around the world, which has been happening at least since 1880, when records started to be kept.
As per the National Oceanic & Atmospheric Administration (NOAA), here are the basic facts: Between 1880 & 1980, the average annual temperature around the world went up 0.07 degrees Celsius per decade, or 0.13 degrees Fahrenheit. Since 1981, the speed of development has sped up and is now 0.18 C per decade, or 0.32 F.
This has caused the average temperature of the Earth to rise by 3.6 F (2 C) since the pre-industrial era. So far, 2016 is the warmest year on record, but it has come close to breaking that record more than once. Both 2019 and 2020 were only a few degrees away from knocking 2016 off its perch. In 2020, the average temperature over land & water was 1.76 degrees Fahrenheit (0.98 degrees Celsius) higher than the 20th century average of 57.0 degrees Fahrenheit (13.9 C).
People are the cause of today’s global warming. By burning fossil fuels, greenhouse gases have been put into the air. These gases trap heat from the sun and make the surface & air temperatures rise. Global warming is the same as climate change, but scientists now use the term “climate change” more often.
What Reasons Global Warming?
The burning of fossil fuels is the main cause of the warming we are seeing now. The greenhouse effect, that is caused by the interplay between the Earth’s atmosphere and the sun’s rays, heats up the planet because of these hydrocarbons.
Josef Werne, a professor of geology & environmental science at the University of Pittsburgh, told Live Science that the basic physics of the greenhouse effect were figured out by a smart guy using only pencil and paper more than a hundred years ago.
That “smart guy” was Swedish scientist Svante Arrhenius, who later won the Nobel Prize in chemistry. Simply put, the sun’s rays hit the Earth’s surface and bounced back as heat toward the atmosphere. This heat can’t escape into space because gases in the atmosphere trap it (good news for life on the planet).
In a paper he gave in 1895, Arrhenius showed that greenhouse gases like Co2 could trap heat close toward the Earth’s surface, & that small changes in the quantity of these gases can make a big variation in how much heat is trapped.
How Greenhouse Gases Lead To Global Warming
Since the start of the Industrial Revolution, people have changed the balance of gases in the air very quickly. When fossil fuels like oil and coal are burned, they give off greenhouse gases like water vapour, carbon dioxide CO2, methane CH4, ozone, and nitrous oxide (N2O). The most popular green house gas is carbon dioxide.
Between about 800,000 years ago and the start of the Industrial Revolution, there were about 280 parts per million of CO2 in the air ppm, meaning there were about 280 molecule of CO2 inside the air per every million air molecules. The National Centers for Environmental Data say that in 2020, the average amount of CO2 in the air was 412.5 ppm. This is the last year for which full data are available (opens in new tab).
The Scripps Institution of Oceanography says that CO2 levels haven’t been which high since the Pliocene epoch, that was about 5.3 million to 2.6 million years ago. According to a study published in the journal Science in 2013, the Arctic was cold for at least part of the year & much warmer than it is now (opens in new tab).