Water is our most important natural resource. Global surface temperatures affect the movement of air currents, the formation of high and low pressure systems, and the movement of water vapor around the atmosphere. All of these factors play a role in determining where, when, and how much it rains. Rising global temperatures will alter this system in many areas, potentially reducing the amount of water available to meet residents’ agricultural, industrial, and recreational needs.
In the western states, where much of the land is arid to semi-arid, mountain snows are a crucial reservoir. As they melt throughout the spring and summer, they keep streams fed and the land relatively green, which reduces the risk of wildfires. However, as temperatures climb and the average year gets warmer, two threats to snow packs emerge. Warmer temperatures mean more rain and less snow in winter, and an early thaw in spring. Smaller, faster-melting snow packs will provide less water and disappear more quickly, leaving already dry areas even drier. This will increase the risk of wildfires, which threaten people’s health and property, as well as decrease the inflow of water into reservoirs. Climate change poses a serious risk to water supplies around the United States. Climate scientists predict that many parts of the country will see a reduction in annual rainfall by 2080. Droughts are likely to become more common and more severe. Water stresses will lead to legal and economic conflicts as cities and states wrangle over how best to allocate diminished water supplies. This is already happening in the southeast, where Georgia and the city of Atlanta are locked in a legal battle with Florida and Alabama over how to divvy up the water in the Lake Lanier reservoir. Atlanta needs the water for its citizens to drink, while Alabama and Florida need it for agriculture, electrical generation, fishing, and recreation. A reduction in the region’s annual precipitation would only sharpen the dispute over the reservoir’s water. As some areas become drier due to climate change, we will see more of these intercity and interstate disagreements about water use. Inevitably, someone will wind up getting the short end of the stick.
Even if you don’t live in an area where climate change will strain your water supplies, the lack of water elsewhere in the country will still hit your pocketbook. Droughts, which will become more common in many areas, damage crops. Smaller crop yields mean higher food prices. A drought in the U.S. and Eastern Europe caused a 10% spike in world food prices in July 2012. Overall food prices have since come down, but one year later U.S poultry and egg prices remained 5.5 and 6.9 percent higher, respectively, due to the drought.
Human Health Effects
Ozone is a good thing when it’s way up in the atmosphere, where we can’t breathe it, protecting earth from damaging UV light. Down at ground level, though, ozone is a nasty air pollutant that can aggravate asthma and heart conditions. Ground-level ozone (smog, basically) forms when nitrogen oxides react with certain chemicals, known as volatile organic compounds, in the presence of sunlight. Warmer temperatures increase the rate at which this reaction occurs, leading to increased ozone levels. As the world gets warmer, the conditions for smog formation will become more favorable. If you live somewhere with a lot of cars or industrial activity, climate change will likely reduce your air quality.
Rising temperatures will also increase the prevalence of some diseases. In some areas, climate change will increase the risk of flooding, either due to more overall rain, or more intense rain. Flooding can spread waterborne diseases such as cryptosporidium; or, if a sewage treatment plant overflows, E. coli. Animal-borne diseases such as West Nile virus will also expand their range. Mosquitos, which carry West Nile virus, need warm weather to survive. Currently, the disease is most common in the southeast, but as the earth warms up and summers get longer and more mosquito-friendly, it will push north, potentially infecting many more people.
Obviously, humans won’t be the only ones affected by climate change. A place’s climate is one of the most important factors in determining what kinds of plants and animals can live there. As earth gets warmer, many species will have to move northward in order to keep within their comfort zones. For example, trout need cold water to survive and reproduce. Trout living in more southerly habitats will find it harder to get by as climate change warms the rivers and streams that these popular sport fish call home. In some places, they may disappear entirely, driven out by changes to their food sources and competition from invading warm-water fish. Climate change will cost us valuable recreational and economic opportunities as it reshapes habitats across the country, driving out local plants and animals and, in some cases, paving the way for unwanted species to move in and take their place.
Ocean acidification is another major problem associated with climate change. The oceans have actually absorbed a lot of the CO2 that we’ve emitted. This has slowed the rate at which our excess CO2 accumulates in the atmosphere, but at the cost of increasingly acidic ocean waters. CO2 in the air reacts with water to form carbonic acid. The more CO2 the oceans absorb, the more carbonic acid they contain. Many marine organisms, including shellfish, corals, and some species of plankton, build their shells out of calcium carbonate, which is very susceptible to acids. As the oceans become more acidic, these organisms will have a harder time building their shells, which they need to survive. These species are economically important, either because people harvest them directly, or because they are part of an ecological community that supports other commercially valuable species. As they struggle to survive in our acidifying oceans, it will be a blow to many people’s livelihoods.
Sea Level Rise
For the many people living in coastal areas, sea level rise due to climate change is a real concern. The oceans are already seven inches higher than they were a century ago, and climate scientists predict that they could rise by another one to five feet by 2100. As global temperatures rise, the Greenland ice sheet will continue to melt, releasing its store of frozen water into the oceans. The Greenland ice sheet contains more than 680,000 cubic miles of ice. If all of it were to melt, it would raise global sea levels by 23 feet. In the short term, sea level rise won’t be that dramatic, but if you live in a state like Delaware or Florida, which have an average elevation of only 60ft and 100ft above sea level, respectively, even a couple of feet are concerning. Higher sea levels pose a threat to coastal transportation infrastructure such as roads, tunnels, and, in cities like New York, subways systems. They will also increase coastal erosion, inundate wetlands and low-lying residential areas, and increase the risk of damaging storm surges.
These changes are largely imperceptible on a day-to-day basis. The oceans are only rising by fraction of an inch each year. But over a century, fractions of an inch can add up to a couple of feet. Climate change is the slow accumulation of small changes, until one day they turn into big ones.
The Bottom Line
Climate change won’t affect everyone the same way, but everyone will be affected in some way. If you live in Indiana, you don’t have to worry about rising sea levels flooding your home, but you will have to worry about decreasing rainfall. Drought and high temperatures will stress crops on the Great Plains and put more pressure on the Ogallala aquifer. In the east, rising sea levels will threaten homes and infrastructure on the coast. Western states will experience more severe fire seasons. And everyone will have to reckon with climate change’s economic effects. Adapting to climate change will cost a lot of money, which will be a major drag on the economy.
Given the expense and disruption of climate change, it makes sense for us to try to minimize its impact. Some of the effects are unavoidable—the CO2 that we’ve already put in the atmosphere won’t be going anywhere for a long time, and the 1.3°F of warming that we’ve already caused is here to stay—but so far they haven’t been too severe. The really dramatic changes are still a few decades’ worth of CO2 away, and we can still avoid them if we start reducing or eliminating our CO2 emissions now.