About a year ago, we wrote about the looming inevitability of a two degree global temperature increase within this century—an increase we couldn’t exceed without irreversible and catastrophic climate events.* In short, scientists have estimated that, in order to stay below the two degree Celsius increase, the atmosphere cannot hold more than 1,000 metric tons of carbon emissions. From the beginning of the Industrial Revolution until 2011, humans were responsible for adding 515 metric tons into the atmosphere—52% of our allotted carbon budget of 1,000 metric tons. This means that the clock is still ticking: from now until the end of time, we can only put 485 billion metric tons of carbon emissions into the atmosphere if we want to stay below a 2 degree temp increase.
If we don’t change our carbon and fossil fuel-reliant behavior, based upon our current usage and yearly temperature increases, we’ll have added the remaining 485 metric tons of carbon into the atmosphere by 2045.. By then, global temperatures will be three to four degrees warmer than they were before the beginning of the Industrial Revolution, and we’ll all be in a lot of trouble.
On the other hand, if we want to attempt to stay below a two degree temperature increase, the world needs to .
Can anybody imagine a scenario in which the developed and developing economies of China, the US, and India—to say nothing of Brazil and the emerging African nations—decrease carbon emissions?** Unfortunately, we can’t either. Just like global populations, the world’s not cutting carbon consumption; it’s increasing it. This past year, China’s emissions grew at 4.2%; the US’ emissions grew at 2.9%; and India’s emissions grew at 5.1%. Only the 28 countries of the EU decreased its emissions by 1.8%.
Based on those increases in carbon emissions, and what they signify for the future, there is now enough carbon floating around in the atmosphere that most scientists agree it will not be possible to stay below two degrees (Or, as they’re saying: “The idea that the world can stay below two degrees Celsius looks increasingly delusional.”). Scientists are coping with this new reality by moving the goalposts: with the two degree increase goal now a foregone conclusion, they’re laying out their projections in more drastic terms.
The UN recently released a report stating that if we don’t entirely eliminate our reliance on fossil fuels by 2100, the world will suffer, at minimum, a four degree increase in temperature by then. At that temperature, life as we know it would not be sustainable; in other words, the planet and its human occupants can’t endure a four degree increase in temperature. Climate scientist Hans Joachim Schellnhuber uses this analogy to explain what our world looks like four degrees warmer: If the human body’s temperature “rises two degrees Celsius, you have a significant fever. If it rises four degrees Celsius or six degrees Celsius, you can die.” What does the four degree increase mean, actually? Well, that’s up for debate. But it won’t be good.
2100 is a mere 85 years away. In order to not be reliant upon fossil fuels by 2100, we’ll have to cut emissions by 60-70% in the next thirty to forty years. In practical terms, that means we’ll all need solar-paneled roofs, battery-operated cars, nuclear power plants, and so on and so forth. No more coal, gas, or oil.
The science of the future is one thing. But we don’t need to look too far to see the ramifications of climate change as it affects us today. Take Sao Paulo, Brazil, for example. Sao Paulo is Brazil’s wealthiest and largest city. In about two weeks, if nothing changes, it will be out of water, as Sao Paulo is in the midst of its worst drought in 80 years.
It’s hard to pinpoint the cause of any phenomenon in nature. But in this case, Brazil’s leading earth scientist says the drought is almost certainly linked to the deforestation of the Amazon and the Atlantic. He recently said this: “Forests have an innate ability to import moisture and to cool down and to favor rain. If deforestation in the Amazon continues, Sao Paulo will probably dry up. If we don’t act now, we’re lost.” (Remember, too, that deforestation leads to an increase in climate carbon emissions because the trees aren’t around to remove carbon from the air through photosynthesis.)
Sao Paulo’s citizens have endured water restrictions for the past nine months, preventing them from running the dishwasher, doing laundry, and showering. If they want clean water, they have to bring buckets, pails, and jars to the emergency reservoir—the emergency reservoir which is just about dry—and lug it home. Residents haven’t had water in their homes for the past month.
Things aren’t looking too good in Sao Paulo.
* Note that in that article, we ignored the fact that many of the best climate and earth scientists think that even a two degree temperature increase is unsustainable. Check out this article for that argument.
** I wrote this post yesterday, but then today President Obama and President Xi announced an agreement in which the US stated it would, by 2025, decrease US carbon emissions by 26-28% below its 2005 carbon emissions level. In return, China agreed to peak its carbon emissions by 2030 and start decreasing its carbon emissions thereafter. Additionally, by 2030, China will get 20% of its energy from renewable energy. It’s the first time China has agreed to any type of carbon emission agreement.