How Would Just 2 Degrees of Warming Change the Planet?
Why do a few degrees make such a big difference?
Increases in temperature and changing rain patterns are associated with the spread of vector-borne diseases (which another organism transmits between humans or from animals to humans), such as Lyme disease and malaria, deMenocal said.
"Even if it [a vector-borne disease] is eradicated locally in a particular region, the weather changes associated with climate change can lead to migrations of these vector-borne diseases to new regions," he said.
Furthermore, because of health concerns, some regions of the globe, such as parts of the Middle East and the American West, may become inhabitable to humans because of extreme temperatures, deMenocal said.
That's because humidity often increases with the heat index. When both are high, the human body is unable to evaporate sweat to cool itself. "If you're unable to evaporate [sweat], you can actually die from exposure," deMenocal said.
Extreme temperatures can also lower productivity among workers. According to a 2014 Bloomberg report on the economic risks of climate change, extreme heat, especially in the American Southeast, may lead to a 3 percent drop in outdoor worker productivity, including among people who work in construction, utility maintenance, landscaping and agriculture. This drop is twice that of the "productivity slowdown" that happened in the 1970s, which likely occured because of high inflation and economic instability, the report said.
All of these threats are just around the corner, deMenocal said. The Earth is anticipated to exceed the 2.7 degrees F (1.5 degrees C) milestone in about 15 years, between 2032 and 2039, deMenocal said. The planet is expected to surpass the 3.6 degrees F (2 degrees C) benchmark between 2050 and 2100, he said.
"If we're on our current emissions scenario, it's even sooner than that," he said. "Even over the last 8,000 years, we haven't seen a temperature extreme this rapid and this fast and large. * (Quoted from https://www.livescience.com/58891-why-2-degrees-celsius-increase-matters.html)
Original article on Live Science.https://www.livescience.com/58891-why-2-degrees-celsius-increase-matters.html