Arctic land regions will see cold extremes warm by as much as 5. Cold spells will also be shorter. The report finds that limiting warming to 1. Reds and oranges highlight lands around the Mediterranean that experienced significantly drier winters during than the comparison period of The report states that up to 50 percent fewer people on Earth may see increased climate change-induced water stress by limiting global warming to 1.
Between and million fewer people are projected to be exposed to increases in water scarcity in at about 1.
Risks for groundwater depletion are projected to be greater at the higher temperature threshold as well. The report finds that at 2 degrees Celsius warming, some places will see an increase in heavy rainfall events compared to at 1.
Heavy rainfall from tropical cyclones is projected to be higher. Loss of Species and Extinction — The report studied , species of insects, plants and vertebrates. Pollinating insects, such as bees, hoverflies and blowflies that support and maintain terrestrial productivity, including agriculture for human food consumption, have significantly greater geographic ranges at 1. At 2 degrees Celsius warming, those numbers jump to 18 percent, 16 percent and 8 percent, respectively.
The consequences of such range changes could be considerable. Take insects, for example. Fires, Extreme Weather, Invasive Species — The report finds risks from forest fires, extreme weather events and invasive species are higher at 2 degrees warming than at 1. Biome Shifts — The report projects entire ecosystems will transform, with about 13 percent of land areas projected to see their ecosystems shift from one type of biome to another at 2 degrees Celsius warming — about 50 percent more area than at 1.
In the Mediterranean biome, desert and arid vegetation is projected to expand above 1. Rainforests and Boreal Forests — According to the report, warming of 1. But that increase is projected to be 0.
About Risks are projected to be highest in South and Southeast Asia, but sea level rise will significantly impact areas all around the world to varying degrees. Slowing the rate of sea level rise would allow humans and ecological systems to better adapt, particularly in small islands, low-lying coastal areas and deltas.
Polar Ice Sheets — The report states, with medium confidence, that at an increased level of warming between 1. The oceans will become more acidic due to higher concentrations of carbon dioxide at 1.
Sea Ice — At 1. Loss of sea ice at 1. Marine Ecosystems — At 1. Glacier National Park in Montana had glaciers in the late s. Today, it has The loss of glaciers can cause the loss of human life, when icy dams holding back glacier lakes destabilize and burst or when avalanches caused by unstable ice bury villages.
At the North Pole, warming is proceeding twice as quickly as it is at middle latitudes, and the sea ice is showing the strain. Fall and winter ice in the Arctic hit record lows in both and , meaning the ice expanse did not cover as much of the open sea as previously observed. According to NASA, the 13 smallest values for maximum winter extent of sea ice in the Arctic were all measured in the last 13 years. The ice also forms later in the season and melts more readily in spring.
Some scientists think the Arctic Ocean will see ice-free summers within 20 or 30 years. In the Antarctic, the picture has been a little less clear. The Western Antarctic Peninsula is warming faster than anywhere else besides some parts of the Arctic, according to the Antarctic and Southern Ocean Coalition.
The peninsula is where the Larsen C ice shelf just broke in July , spawning an iceberg the size of Delaware. Now, scientists say that a quarter of West Antarctica's ice is in danger of collapse and the enormous Thwaites and Pine Island glaciers are flowing five times faster than they did in The sea ice off Antarctica is extremely variable, though, and some areas have actually hit record highs in recent years. However, those records could bear the fingerprints of climate change, as they may result from land-based ice moving out to sea as the glaciers melt or from warming-related changes to wind.
In , though, this pattern of record-high ice abruptly reversed, with the occurrence of a record low. On March 3, , Antarctic sea ice was measured at an extent of 71, square miles , square kilometers less than the previous low, from Global warming will change things between the poles, too.
Many already-dry areas are expected to get even drier as the world warms. The southwest and central plains of the United States, for example, are expected to experience decades-long "megadroughts" harsher than anything else in human memory. The main driver, the researchers found, is the increasing evaporation of water from hotter and hotter soil. Much of the precipitation that does fall in these arid regions will be lost. Meanwhile, research found that many areas will likely see less rainfall as the climate warms.
Subtropical regions, including the Mediterranean, the Amazon, Central America and Indonesia, will likely be hardest hit, that study found, while South Africa, Mexico, western Australia and California will also dry out. Another impact of global warming: extreme weather. Hurricanes and typhoons are expected to become more intense as the planet warms.
Hotter oceans evaporate more moisture, which is the engine that drives these storms. That means more wind and water damage on vulnerable coastlines.
Paradoxically, climate change may also cause more frequent extreme snowstorms. According to the National Centers for Environmental Information, extreme snowstorms in the eastern United States have become twice as common as they were in the early s.
Here again, this change comes because warming ocean temperatures lead to increased evaporation of moisture into the atmosphere. This moisture powers storms that hit the continental United States. The earth's marine ecosystems are under pressure as a result of climate change. Oceans are becoming more acidic, due in large part to their absorption of some of our excess emissions. As this acidification accelerates, it poses a serious threat to underwater life, particularly creatures with calcium carbonate shells or skeletons, including mollusks, crabs, and corals.
This can have a huge impact on shellfisheries. The polar regions are particularly vulnerable to a warming atmosphere. Average temperatures in the Arctic are rising twice as fast as they are elsewhere on earth, and the world's ice sheets are melting fast. This not only has grave consequences for the region's people, wildlife, and plants; its most serious impact may be on rising sea levels.
By , it's estimated our oceans will be one to four feet higher, threatening coastal systems and low-lying areas, including entire island nations and the world's largest cities, including New York, Los Angeles, and Miami as well as Mumbai, Sydney, and Rio de Janeiro.
There's no question: Climate change promises a frightening future, and it's too late to turn back the clock. We've already taken care of that by pumping a century's worth of pollution into the air nearly unchecked. That, of course, is the bad news.
But there's also good news. By aggressively reducing our global emissions now, "we can avoid a lot of the severe consequences that climate change would otherwise bring," says Haq.
From dusty fields in the San Joaquin Valley, fungal spores are wafting up, exposing more and more farmworkers to the disease. In an imaginary world where carbon pollution stops with a flip of the switch, the planet warms over the next 50 years to about 2. Earth's surface today is 1. But starting in , the model has the planet beginning to gradually warm again, with average temperatures climbing another degree over the following years, and sea levels going up by at least three metres.
Under the second scenario, Earth heats up to levels that would tear at the fabric of civilisation far more quickly, but ends up at roughly the same point by The core finding -- contested by leading climate scientists -- is that several thresholds, or "tipping points", in Earth's climate system have already been crossed, triggering a self-perpetuating process of warming, as has happened millions of years in the past.
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