Global warming is concerning a growing number of environmentalists, climate scientists, and governments worldwide. Despite the growing evidence indicating that civilization may be in danger, there are politicians, scientists, and interest groups that global warming is a hoax. Whether folks understand global warming or not, the National Oceanic and Atmosphere Administration (NOAA) proposed top evidence supporting that global warming is real.
1. Global rise in surface temperature
Climate fluctuated in temperature throughout Earth’s history due to geological upheavals, a slight change in the planet’s orbit, or when the sun’s energy production varied. However, in the last 200 years, human activity is the primary cause of the of rising global temperature, raising it by about 1.4°F since the early 20th century, according to NCDC. By taking samples from the Antarctic ice cores, scientists have also measured the amount of carbon dioxide and methane and found that they have increased by about 38 percent and 148 percent, respectively, since the dawn of the Industrial Revolution in the 1750s.
2. Sea level rising
Over the past 100 years, sea levels are rising at an average rate of 1.7 millimeters per year based on tide gauge observations. Since 1993, however, the rate of rising sea levels have increased to about 3.5 millimeters per year. Recent satellite imaging also revealed that worldwide sea levels has risen between 4 to 8 inches. When climate temperature increases, water absorbs some of that heat which causes the oceans to expand. It also causes ice to melt, particularly from Greenland, polar caps, and mountain glaciers, which contributes to greater amounts of liquid water. Higher temperature also causes large chunks of Antarctica’s ice to break off, such as the one that broke off from Pine Island Glacier on July 2013. At this rate, it is very likely that, by 2100, major coastal cities will be swamped or partially submerged, such as New York City, Miami, and London.
3. Snow cover retreating
The North Pole may no longer have enough snow covering for Santa’s home. According to the National Ice & Snow Data Center, as of July 2011, the amount of snow covering in the Northern Hemisphere was at a record low. The 2011 amount was 2.92 million square miles below 1979 average and 865,000 square miles below 2000 average. The air temperature around the North Pole was 11 to 14°F higher than average. When the 2011 satellite images of the North Pole were compared among those between 1979 and 2010, snow and ice coverings were melting at an earlier time, sometimes as early as 50 days. Other evidence of global warming include larger and more frequent pockets of ponds and lakes in the spring.
4. An 800,000-year-old record
Global warming had happened several times during the last 10 to 15 million years, but never at rate that is happening recently. Scientists examined trapped air bubbles in the Antarctic ice core that recorded about 800,000 years of Earth’s atmospheric history. Within this time frame, the Earth had a fluctuation of 170 to 300 parts per million (ppm) of carbon dioxide. This equates to about 35 percent of the amount of atmospheric carbon dioxide since the dawn of the Industrial Revolution. With the burning of fossil fuel contributing to about 80 percent of the rise in carbon dioxide gas and with deforestation and modern agriculture contributing to about 20 percent of the remaining amount, current levels are nearly 400 ppm, according to NOAA. This sharp jump in carbon dioxide level is the highest ever in the last 800,000 years.
5. The sun isn’t getting hotter
The sun may seem brighter and hotter for some people, but that is more likely a perception issue rather than an actual increase of heat and luminosity of the star. NOAA stated that the sun has maintained its natural 11-year-cycle of small energy fluctuations with no net increase between 1979 to 2009. At the same time period, however, global temperature had greatly increased, nullifying the myth that the sun has anything to do with the rapid rise in global warming.
Global warming isn’t likely to go away in a lifetime. If it took about 200 years to reach current levels of global temperature and carbon dioxide concentration — and with the current rates increasing — if may take another few centuries to undo the damage.
By Nick Ng