NASA's ongoing global temperature analysis has found that the average global temperature has increased by 0.8 degrees Celsius (1.4 degrees Fahrenheit) since 1880. Notably, the agency found that two-thirds of this temperature increase has happened since 1975 — and five of the earth's warmest years on record have occurred since 2010. While this increase may seem small, it's really significant when considered on a global scale.

"A one-degree global change is significant because it takes a vast amount of heat to warm all the oceans, atmosphere, and land by that much," NASA described in an article on its Earth Observatory website. "In the past, a one-to two-degree drop was all it took to plunge the Earth into the Little Ice Age. A five-degree drop was enough to bury a large part of North America under a towering mass of ice 20,000 years ago."

A 2018 report from the World Wildlife Fund (WWF) revealed that, if carbon emissions continue at the current rate, almost half of the plant and animal species in the world's most diverse ecosystems could become extinct. These ecosystems include places like the Amazon and the Galapagos.

“Hotter days, longer periods of drought, and more intense storms are becoming the new normal, and species around the world are already feeling the effects,” Nikhil Advani, the lead specialist for climate, communities, and wildlife at WWF, said in a press release about the report. “While we work to ratchet down emissions, it’s critical we also improve our understanding of species’ response to climate change and develop strategies to help them adapt.”

Due to warming ocean temperatures that stem from climate change, Antartica's ice sheets are melting at an unprecedented rate. A 2018 study in Nature magazine found that the Antarctic ice sheet lost 3 trillion metric tons of ice from 1992 to 2017.

"People should be concerned that Antarctica is clearly feeling the effects of climate change and it’s responding to changes in ocean temperature,” Andrew Shepherd, the study's lead author, told The Los Angeles Times.

The paper also noted that the melting of this ice sheet will continue to contribute to sea level rise, something that could eventually displace many people who reside in coastal areas around the world.

A 2017 study published in the Proceedings of the National Academy of Sciences found that global sea levels have risen around 8 inches worldwide since 1880. Moreover, sea levels have been rising at a slightly increased rate each year.

Heightened sea levels have already caused flooding problems for many cities around the world, including in the United States. A 2018 study from the National Oceanic and Atmospheric Administration (NOAA) found that high tide flooding, which occurs due to sea level rise, now happens twice as often in the U.S. as it did 30 years ago.

Ben Horton, an environmental researcher from Rutgers University, told USA Today that the study should serve as "a warning, a shot across the bow. Across the whole of the U.S. coastline, we are in dire need of action."

Due to resource and food shortages, health impacts, and displacement brought on by climate change, there's a real possibility that many people could return to extreme poverty in just 20 years. The World Bank's 2018 report on climate change and health found that "climate change could see more than 100 million people return to extreme poverty by 2030 unless concerted action is taken."

The same World Bank report also found that, as the planet warms, humans will be increasingly affected by deadly and life-altering diseases. These effects are already being felt, particularly in developing countries. As the report described:

Climate change influences health through changing the distribution and occurrence of vector-borne diseases... Warming of 2-3°C is estimated to increase the number of people at risk of malaria by... more than 150 million people.

[Moreover], climate change is also closely linked with increased incidence of dengue – a mosquito-borne disease whose transmissibility has increased by between 3 and 6 percent due to climate change since 1990.

A study released by the European Academies' Science Advisory Council last year found that climate change-induced extreme weather events are happening more frequently than ever before. And they only stand to increase over time. As the report described:

Globally... the number of floods and other hydrological events have quadrupled since 1980 and have doubled since 2004, highlighting the urgency of adaptation to climate change. Climatological events, such as extreme temperatures, droughts, and forest fires, have more than doubled since 1980. Meteorological events, such as storms, have doubled since 1980.

In the top part of the world's oceans (the first 2,300 feet or so), there has been warming of more than 0.4 degrees Fahrenheit since 1969, according to NASA. More recent studies, including one published in Science in January, found that the world's oceans may be increasing in temperature at an even faster rate.

The International Union for Conservation of Nature reported that rising ocean temperatures can present a host of problems for humans and the environment, including contributing to sea level rise (due to ice melting) and making extreme weather events more likely.

In 2017, The Guardian reported that major international cities could be engulfed by water if global warming reaches 3 degrees Celsius (37.4 degrees Fahrenheit) above pre-industrial levels by 2100, as some models currently predict. Some of those cities would include Osaka, Rio de Janeiro, Shanghai, and Miami.

The science is clear that climate change is already having a huge impact on the Earth in myriad ways. If action isn't taken soon to curb global warming, these will could become even more extreme.