Physical and financial
Climate change is the Earth’s response to increased carbon dioxide in the atmosphere. These greenhouse gases trap infrared heat from the sun. That has raised the earth’s average temperature at least 1.2 degrees Celsius since the late 19th century.
Climate change is nothing new in the Earth's history. But previous changes occurred much more slowly. Slight changes in the earth’s orbit created those warming and cooling periods. Scientists agree that humans are causing this bout of climate change.
Income inequality is tied to climate change. A recent study found that the planet's wealthiest 1 billion people emit 60 percent of greenhouse gases. The poorest 3 billion produce only 5 percent. Facts
The increase in global warming has created other problems. The oceans are absorbing carbon dioxide from the atmosphere. In response, they’ve become 30 percent more acid since the beginning of the Industrial Revolution. They’ve also become warmer. The top 2,300 feet are 0.3 degrees warmer since 1969, causing them to expand. When ocean water expands, sea levels rise.
In 2017, the Arctic had 448,000 square miles less sea ice than normal. The ice is melting more than usual in the summer, but not regaining its mass in the winter. A 2018 study found the Arctic Ocean has lost 95 percent of it oldest, thickest ice. That ice is the glue that keeps the Arctic frozen in the summer.
Less ice means less white snow to reflect the sun's rays. That speeds up the melting process. Scientists predict that by 2050 there will be no Arctic ice in the summer. The dark ocean that replaces it will absorb even more heat.
The Arctic is warming faster than the rest of the region. The differential between the two causes the jet stream. As it weakens, it brings cold air south and pumps warm air north. That's what causes blizzard-like conditions along the U.S. East Coast.
The resulting onslaught of fresh water is shifting the global circulation of the oceans. Typically, surface waters traveling toward the poles become colder. As they chill, they become denser and sink. Once the hit the ocean floor, they roll back toward the equator. The cycle is called convection.
Melting glacial ice puts fresh water into the equation. It is less dense than salty water. As a result, it doesn't sink as it should. It stays on the ocean's surface, slowing the "ocean conveyor belt."
The "Atlantic Meridional Overturning Circulation" is the conveyor belt that brings tropic water to the shores of Great Britain and northern Europe. As it slows, that area cools, since it's at the same latitude as Newfoundland in North America. This Gulf Stream conveyor belt has slowed 15 percent since 2008. It's now the weakest in the last 1,600 years. As a result, the ocean cools south of Greenland and warms along U.S. Atlantic coast. When Greenland stays cooler in the summer, it allows warm air from the south into Europe.
It helped cause the 2015 European heat wave.
A similar event is happening near the Antarctic. Freshwater from melting glaciers blocks cold salt water from sinking to the ocean's floor. As a result, warm water is melting the ice shelves from underneath. It's triggering a feedback loop that will melt the glaciers even faster. The Antarctic ice caps are melting by 1.6 meters per year. Before 1992, they were only melting at a rate of 3.8 centimeters a year.
Between 60 and 90 percent of the world’s fresh water is frozen in the ice sheets of Antarctica. If it all melted, it would increase sea levels by 200 feet.
So far, melting polar ice sheets have increased sea levels 8.9 inches in the last 100 years. Glaciers and snow cover are also shrinking. That heats up the atmosphere even more since snow reflects heat back into space. Higher temperatures have created more damaging and frequent natural disasters.
In 2018, a new development is worrying scientists. Dark algae are spreading across the world's ice. As temperatures warm, it creates the perfect environment for these blooms. Dark algae absorb more sun, melting the ice even faster than previously thought. Economic Impact
In May 2018, Stanford University scientists calculated how much global warming would cost the global economy. If the world's nations adhered to the Paris Climate Agreement, and temperatures only rose 2.5 percent, then the global gross domestic product would fall 15 percent. If temperatures rose to 3 degrees Celsius, global GDP would fall 25 percent. If nothing is done, temperatures will rise by 4 degrees Celsius by 2100. Global GDP would decline by more than 30 percent from 2010 levels. That's worse than the Great Depression, where global trade fell 25 percent.
The only difference is that it would be permanent.
The World Employment and Social Outlook 2018 estimated that climate change threatens 1.2 billion jobs. The industries most at risk are agriculture, fisheries, and forestry. Maine is already seeing a decline in its lobster catches. Natural disasters have already cost 23 million working life years since 2000. On the other hand, efforts to stop climate change would create 24 million new jobs by 2030.
As America experiences more extremely hot days, food prices are rising. That's because corn and soybean yields in the United States plummet precipitously when temperatures rise above 84 degrees Fahrenheit. Those crops feed cattle and other meat sources. It's created spikes in beef, milk, and poultry prices. Worker productivity declines sharply, particularly for outdoor jobs. That further increases the cost of food.
A 2019 study found that global warming has pushed global fish yields down 4% since 1920. That's 1.4 million metric tons. In the North Atlantic and Sea of Japan, that decline is 35%. That affects Atlantic cod, haddock, and herring. Many species are threatened with extinction. That affects the 3 billion people who rely on fish for their primary source of protein. It also affects the $100 billion fishing industry and the 56 million people employed. It especially affects the United States, which imports 90% of its seafood.
Climate change is causing mass migration around the world. Immigrants are leaving flooded coastlines, drought-stricken farmlands, and areas of extreme natural disasters. Since 2008, extreme weather has displaced 22.5 million people according to the United Nations High Commissioner for Refugees. By 2050, climate change will force 700 million people to emigrate.
In 2017, the U.S. Department of Defense reported that climate change is a “direct threat” to U.S. national security. Extreme weather and rising sea levels caused by global warming endanger 128 military bases. A 2018 Pentagon survey revealed that U.S. Naval Academy in Annapolis, Md. has experienced storm surge flooding and hurricane damage. The Cape Lisburne Long Range Radar Station in Alaska has lost a seawall from extreme weather. In response, Congress asked DoD to identify the 10 most vulnerable sites and recommend solution strategies.
Climate change creates unpredictable and violent storms, drought, and floods. That's according to John P. Holdren, Director of Woods Hole Research Center, and other experts. A 2017 poll showed that 55 percent of Americans believe that climate change made hurricanes worse. That's up from the 39 percent who said so 10 years ago. As a result, 48 percent reported being afraid of climate change. Here are examples that prove their point. These natural disasters have also taken a toll on the economy in the last seven years.
Munich Re, the world's largest reinsurance firm, blamed global warming for $24 billion of losses in the California wildfires. It warned that...