Every year, humans dump 30 billion tons of carbon dioxide (CO2) into the atmosphere. That’s four tons for every person on Earth. Since the start of the industrial revolution, we have changed the amount of CO2 in the atmosphere from 280 ppm (parts per million) to more than 380 ppm in 2008. That level has not been reached anytime in the last 650,000 years.
Sunlight hits the Earth and is converted to heat. A blanket of CO2 and other greenhouse gases retains some of that heat. Some greenhouse effect is needed to sustain life on Earth. Without it, the average global temperature would be 0°F!
Global warming is excess greenhouse effect. It’s like adding an extra blanket over the Earth. If we keep operating as we have been, by the year 2100 the average global temperatures could rise by more than 10°F (6°C).
Effects of Climate Change
The climate is a complicated system. Adding an extra blanket doesn’t raise the temperature uniformly. Most places will get hotter, but as weather patterns change some will cool. Some places will have more floods, others will have more prolonged droughts.
Extreme weather events will happen more often. As sea temperatures rise, hurricanes will become stronger. Ocean currents could be disrupted, potentially causing a mini ice age in North America and Europe. Glaciers will melt, potentially leaving almost one billion people without a source of fresh water.
Resource wars will become a serious security issue for the United States. Large numbers of species unable to adapt to the fast changes will become extinct. And, sea levels will rise.
There is a lot of water locked in the ice sheets of Greenland and Antarctica. If the Greenland ice sheet completely melted, sea levels would rise 20 feet. While it might take more than a century for that to happen, a rise of even a few feet would drastically affect Long Island and other costal areas.
Point of no return
Does it matter if we act now or wait to see how bad the problem is? YES! If we wait to act, we might reach a point of no return, after which climate change cannot be halted.
There are many positive and negative feedback loops in the climate. A positive feedback acts as an accelerator, and a negative feedback acts as a brake.
A negative feedback loop in the climate dampens the effect of our carbon pollution. For example, the oceans absorb some of the CO2 we emit. But, eventually the oceans could become saturated, and that brake we have been counting on might not continue to work. There is evidence this has already started happening.
A positive feedback loop in the climate feeds off our pollution. The scariest positive feedback loops are those that haven’t kicked in yet. For example, climate change is beginning to cause the permafrost to melt. As it melts, it will release the carbon beneath it. If only 1% of that carbon were released each year, it would exceed the total yearly amount dumped by humans. The additional CO2 would cause more permafrost to melt, releasing even more carbon. At that point, even if we somehow cut emissions to zero, catastrophic climate change would be unstoppable.
So we need to act before it’s too late.