other species, oceans, agriculture, and a range of human activity. In turn, these consequences are interacting with other elements of nature and human existence, creating complex feedback loops and further unintended consequences.
The interactions are complex and numerous and we’re still not clear on what some of the further consequences will be, but in this chapter, we’ll examine some of the costs of upsetting the earth’s carbon cycle.
A World of Extreme Weather, Water, and Food
INCREASINGLY FREQUENT AND severe heat waves, heavy rain and snowfall events, hurricanes, tornadoes, wildfires, and floods—unusual weather and its effects are everywhere, and getting worse as the planet warms. California has been experiencing severe drought since 2011. Temperatures in Spain, Portugal, India, and Pakistan reached record levels in 2015, sparking wildfires and causing thousands of deaths and heat-related ailments. In the same year, heavy rains, flooding, and an unusually high number of tornadoes caused extensive damage and death in Texas, Oklahoma, and parts of Mexico.
The likely causes are complex: a stuck jet stream, El Niño, natural variation, and climate change. Even though it’s difficult to link all events directly to global warming, climate scientists have warned for years that we can expect these kinds of extremes to continue and worsen as the world warms. Some hypothesize that the strange behaviors of 2015’s jet stream and El Niño are related to climate change, with shrinking Arctic sea ice affecting the former.
Hurricane Sandy, which wreaked havoc on Caribbean nations and the U.S. East Coast in October 2012, offered a glimpse into our future.
Does that mean climate change caused Hurricane Sandy? Not necessarily. Experts know that tropical Atlantic storms are normal in fall. This one and its impacts were made unusually harsh by a number of converging factors: high tides, an Arctic weather system moving down from the north, and a high-pressure system off Canada’s East Coast that held the storm in place.
But most climate experts are certain that the intensity of the storm and the massive damage it caused were in part related to changing global climate. Global warming causes sea levels and ocean temperatures to rise, which results in more rainfall and leads to a higher likelihood of flooding in low-lying areas. Scientists also believe 2015’s record Arctic sea-ice melt may have contributed to the high-pressure system that prevented Sandy from moving out to sea. In short, the storm and the unprecedented flooding and damage are exactly what climate scientists have been telling us to expect as global temperatures rise.
Extreme weather events, including heat waves and drought, are no longer just model-based predictions. NASA scientist James Hansen, who sounded the alarm about climate change in 1988, wrote in the Washington Post in 2012, “Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change.”1
A number of studies indicate a clear connection between increasing extreme weather and climate change.2 One, by climatologists at the U.S. National Center for Atmospheric Research in Colorado, looked at rising global atmospheric and sea surface temperatures, which have increased water vapor in the atmosphere by about 5 percent since the 1950s. According to the 2015 paper, published in Nature Climate Change, “This has fuelled larger storms, and in the case of hurricanes and typhoons, ones that ride atop oceans that are 19 centimetres higher than they were in the early 1900s. That sea-level rise increases the height of waves and tidal surges as storms make landfall.”
Because of the way the planet and its systems balance energy, extreme precipitation in some areas is increasing more quickly than overall rainfall. Rain is caused by water vapor cooling enough to condense into liquid when the atmosphere cools. But with more greenhouse gases warming the atmosphere, water vapor can build up, leading to heavy rain and snow events that are increasing in frequency and severity. With more moisture and energy in the atmosphere, and warmer oceans, the world can also expect more intense hurricanes. Besides flooding, extreme precipitation can cause crop damage and loss, soil erosion, water contamination, and more. Because water vapor is often held for longer by a warmer atmosphere, and released in extreme events over smaller areas, other areas often get less overall precipitation than before, leading to droughts in some places.
A Stanford University study found “accumulation of heat in the atmosphere can account for much of the increase in extreme high temperatures, as well as an average decrease in cold extremes, across parts of North America, Europe and Asia” but also concluded the influence of human activity on atmospheric circulation, another factor in climate change, is not well understood.3
What scientists do know is that moist air rises as it is heated near the equator. Once it is high enough to cool, the moisture falls as tropical rain. The dry air then moves north and south, normally dropping at the subtropics. With a warmer planet, it travels farther, causing drying conditions farther north and south. This could help explain ongoing drought conditions in California and other parts of the U.S. Southwest. A 2016 paper published in Nature Climate Change examined the effects of atmospheric circulation and increased water vapor on storms and flooding in England during winter 2013–14.4 The researchers used model simulations and found that the historic precipitation and flooding were caused not just by increased moisture in the air but also by increases in the number of January days with westerly flow.
The damage that climate change is causing, which will get worse if we fail to act, goes beyond the hundreds of thousands of lives, homes, and businesses lost; ecosystems destroyed; species driven to extinction; infrastructure smashed; scarce or polluted food and water in many areas; and people inconvenienced. It will even devastate the one thing that many corporate and government leaders put above all else: that human creation we call the economy—the very excuse many of our leaders use to block environmental protection and climate action.
The U.S. Environmental Protection Agency (EPA) reported, “Between 2011 and 2013, the United States experienced 32 weather events that each caused at least one billion dollars in damages.” According to Hansen, the Texas drought in 2011 alone caused $5 billion in damage. Repairing the damage from Hurricane Sandy in the U.S. is expected to cost at least $50 billion. And as former World Bank economist Nicholas Stern has pointed out, slowing climate change will cost us, but doing nothing will cost far more.
Earth is clearly experiencing more frequent extreme weather than in the past, and we can expect it to get worse as we burn more coal, oil, and gas, and pump more carbon dioxide and other greenhouse gases into the atmosphere. This can have profound and costly impacts on everything from agriculture to infrastructure, not to mention human health and life.
Increasing extreme weather threatens global water supplies and food security. We’ve already seen prolonged droughts affecting food supplies in what were once productive food-growing areas, such as California, parts of Africa, and elsewhere in the world. Flooding also destroys crops and degrades and erodes soil, and changing weather patterns—altered growing seasons, less predictable conditions, and shifting climate zones—are making food production a challenge. Melting glaciers and changes to the earth’s hydrologic cycles will affect the availability of water for drinking and growing food. As the world has come to depend more and more on globalized food delivery, climate change will also put pressure on the ability to rationalize these systems. Transporting food over long distances will become increasingly difficult, unless we can find ways to ship products without burning large amounts of some of the most polluting fossil fuels. That means shifting to more local food production, but that is threatened by the difficulty many areas are experiencing, and will experience even more as the world continues to warm, to produce food for local populations. Increasing degradation and loss of productive soils because of industrial agriculture practices
