Scientists have coined a term for the unique geological era in which we are living, the “Anthropocene,” an epoch in which civilization itself has significantly and unmistakably altered the atmosphere through the development of agriculture and industry. Indeed, the makeup of the atmosphere has changed. Although in the past there have been large fluctuations in carbon dioxide concentrations between interglacial periods, the time frame in which the recent increase has been occurring is much shorter, meaning that the resulting changes in climate will happen at a rate unprecedented in human history.
In pre-industrial times, the concentration of carbon dioxide in the atmosphere was around 280 ppm (parts per million).[i] Many climate scientists assert that the safe level of carbon dioxide in the atmosphere is below 350 ppm, which we have already surpassed; current levels are above 400 ppm, perhaps permanently.[ii]
Climate scientists warn that if the global temperature increases by another two degrees Celsius (3.6 degrees Fahrenheit), catastrophic and irreversible damages could be triggered. At our current rate of warming, we could reach that two-degree tipping point by 2050.[iii] Never has the need for decisive action to mitigate climate change been more urgent, as the signs of climate change are becoming more apparent every day.
The mounting extreme weather and natural disasters of the past several years are a preview of what is likely to happen increasingly going forward. In 2015, 2,500 people were killed in India’s second deadliest heat wave, while Pakistan suffered 2,000 fatalities. Myanmar expereienced its worst flooding in decades, affecting more than one million people.[iv] For the past few months Thailand has experienced the worst heat wave in the country’s history, with record high temperatures of 112 degrees Fahrenheit. The heat wave has generated a new record for energy consumption and produced numerous health warnings. Several other countries in Southeast Asia have endured searing temperatures. Cambodia and Laos set new all-time record highs for any day of the year during April. In addition, Malaysia, Singapore, and Vietnam have all come close to breaking national heat records.[v]
Record-setting floods hit Texas and Kansas this past May; at the same time the worst drought in two thousand years forced communities in California to cut water usage by 25%. In mid-June temperatures soared across the Southwest, with an historic heat wave peaking at 125 degrees Fahrenheit. Massive wildfires broke out in New Mexico, California, and Arizona, covering tens of thousands of acres.[vi]
Although it can be difficult to directly link these disasters to the effects of climate change, there is increasing evidence for the link, and they certainly provide a preview of what is to come on a hotter planet. As Dr. Rajendra Pachauri, the chief of the U.N.’s Intergovernmental Panel on Climate Change (IPCC), puts it, “We are sure that the kinds of events that we've seen recently are likely to become much more frequent and much more severe.'' New research from the National Academy of Sciences indicates that scientists can now determine with some confidence the degree climate change has influenced some extreme weather events.[vii]
Global average surface warming in degrees Celsius over the past century. (Photo: IPCC)
As is already becoming apparent, increased global temperatures will make wildfires more common, turning burning forests into major emitters of carbon dioxide rather than sinks to take carbon dioxide out of the atmosphere. A hotter planet also means melting Arctic tundra, or permafrost. Melting permafrost can result in the release of billions of tons of greenhouse gases, including methane, which is about twenty times more powerful in its ability to trap heat than carbon dioxide. The damage from melting permafrost could be disastrous, as the amount of greenhouse gases contained in the tundra far exceeds that which has already been emitted directly by humans since the Industrial Revolution. Melting permafrost is already frighteningly apparent in Siberia, where greenhouse gas emissions from the Arctic tundra have increased by a staggering one third in only five years. The release of these gases on a large scale would dramatically accelerate global warming.[viii]
The Arctic permafrost is only one source of troublesome melting. According to a 2012 study, the Greenland and Antarctica ice sheets together are losing more than three times as much ice each year as they were in the 1990s. About two-thirds of the loss is coming from Greenland, with the rest from Antarctica.[ix]
In the last century, the global mean sea level rose about 7.5 inches. By 2100, according to the 2014 IPCC Report, sea levels will likely rise between 10 and 22 inches, and beyond that melting ice sheets could contribute to a rise of up to 23 feet. Some scientists see these projections as quite conservative -- a study this past spring concluded that oceans could rise more than six feet by the end of the century and the melting of ice on Antarctica alone could cause seas to rise more than 49 feet by 2500.[x]
It turns out that the seas along the Atlantic coast of the United States are rising as much as three to four times the global average due to variations in ocean circulation.[xi]
Norfolk, VA, is just one example of a coastal community that is already experiencing the impact of these higher seas. Like many cities, it was built on filled-in marshland, and is now compacting and sinking. Combined with sea levels that have risen 14.5 inches since 1930, this has resulted in constant flooding, which causes major problems with infrastructure and plummeting housing prices, even as the city tries to adapt by raising roadways.[xii]
Rising sea levels around the world could eventually completely submerge low-lying coastal areas, destroy important ecosystems, and displace millions of people.
Indeed, the U.N. Refugee Agency (UNHCR) ccontends that the humanitarian crises that could be triggered by the effects of climate change have been vastly underestimated, with natural disasters and environmental degradation resulting in geopolitical instability, mmillions of refugees, and violent conflict over diminishing essential resources such as water, land, and food. "Climate change is already undermining the livelihoods and security of many people," the U.N. agency observed in a 2009 report, "exacerbating income differentials and deepening inequalities." Nine out of every ten natural disasters today, it concluded, are climate-related. [xiii]
In particular, climate change has prompted serious concerns about food scarcity. Unfavorable conditions for growing crops such as drought and excessive rainfall and extreme weather events such as flooding and tornadoes are expected to get worse. This would be a huge problem even if our population was expected to hold steady, but in fact there will be an estimated two billion more mouths to feed by 2050. The FAO estimates that harvest yields will need to increase by 70% by 2050 in order to feed those people, with a needed annual increase in rice and wheat yields of 1.2 to 1.4%. Growth rates in annual yields of rice and wheat have been faltering at 0.6 and 0.7%, however, which clearly will not be enough to meet predicted demand in forty years.[xiv] Oxfam predicts that this future mismatch between supply and demand will result in a doubling of food prices by the year 2030, as well as millions of more people not having enough to eat.[xv]
We are at a crucial juncture in human history and the stakes for human survival have never been higher. Ignoringclimate change and waiting for a “more convenient” time to deal with it will not make it go away. Moreover, it will only be more difficult and expensive to effectively mitigate the consequences of climate change in the future. Local governments must lead the way forward in the face of continued federal inaction. Tompkins County has committed itself to reducing its emissions 80% by 2050, but it will take a sustained effort on the part of citizens and their leaders to achieve this goal. Bringing global emissions down to a safe level for humanity will require all hands on deck if we are to alter our trajectory for the better. Failure is not an option.