In the past, I have raised the specter of extreme temperature by focusing on the impact 104 degrees Fahrenheit has on the photosynthetic machinery of common crops like corn and soy bean. (Spoiler alert: photosynthesis in these crops stops at 104o F.)
Now comes a warning from Jim Yong Kim. He is warning catastrophic consequences will result if world average temperatures rise by 4o Celsius (about 7 degrees Fahrenheit).
There is no certainty that adaptation to a 4o C world is possible.
Who is this wide-eyed doomsayer? What does this "doomsday scenario" have to do with his day job and why should anyone listen to him? Good question....
Jim Yong Kim is president of the World Bank. As the Washington Post reports, a recent study by the World Bank, titled:
Turn Down the Heat: Why a 4o C Warmer World Must be Avoided (warning PDF) has found that:
Despite the global community’s best intentions to keep global warming below a 2°C increase above pre-industrial climate, higher levels of warming are increasingly likely. Scientists agree that countries’ current United Nations Framework Convention on Climate Change emission pledges and commitments would most likely result in 3.5 to 4°C warming. And the longer those pledges remain unmet, the more likely a 4°C world becomes.
This is a problem for a variety of economic reasons that are obvious. But there is a new term creeping in to the language of these reports that bears notice:
...a 4°C world is so different from the current one that it comes with high uncertainty and new risks that threaten our ability to anticipate and plan for future adaptation needs.
We are not talking about adaptation of business practices here. We're talking adaptation of the species to a new environment. The dire language is intentional. As the forward opens with the following:
It is my hope that this report shocks us into action. Even for those of us already committed to fighting climate change, I hope it causes us to work with much more urgency.
The reason for their concern is the risk-based approach they have taken is defined as "impact multiplied by probability." In other words, a low probability event with high impact is just as serious as a high probability event with lower impact. The potential impact here is enormous, and the probability is increasing. Taken together the risk cannot be ignored. To put the impact in perspective, the study notes:
It is also useful to recall that a global mean temperatureincrease of 4°C approaches the difference between temperatures today and those of the last ice age, when much of central Europe and the northern United States were covered with kilometers of ice.
The big difference between now and the potential increase? It will occur in decades, not millenia. In geological terms this is as sudden a shock to the system as running a car into a wall at 100 miles an hour.
Here's something I was surprised to learn. Once I read it, it made perfect sense.
The global oceans have continued to warm, with about 90 percent of the excess heat energy trapped by the increased greenhouse gas concentrations since 1955 stored in the oceans as heat. The average increase in sea levels around the world over the 20th century has been about 15 to 20 centimeters. Over the last decade the average rate of sea-level rise has increased to about 3.2 cm per decade. Should this rate remain unchanged, this would mean over 30 cm of additional sea-level rise in the 21st century.
That makes sense because water is a great heat sink. In simple language, this means the hotter the planet gets, the water warms up slower than the land and air, but it stays warm longer. The rise is slow, but steady. This is one reason we are seeing bleaching of coral reefs. Since most of the oxygen in our atmosphere comes from algae growing in the ocean, heating that up too much is not a good thing. However, long before that happens, we will see significant increases in sea level as the polar ice continues to melt. 30 cm rise in water levels is just under a foot. That doesn't sound like much, but when you consider most people on the planet live near a coast, you can see who this will have a huge impact around the world. Although the pattern is complex, the consequences are still severe. As one
reference source notes these will include the following:
Inundation – SLR may cause increased wave over-topping, tsunami inundation, and hurricane storm surge with negative impacts to low-lying environments, ecosystems, and developed areas including coastal roads and communities.
Erosion – SLR may lead to changes in coastal sediment transport and storage resulting in erosion of beaches, dunes, bluffs, estuarine shorelines, and tidal wetlands. Fine sediment released by erosion may impact coastal water quality, and combined with ocean acidification and warming cause negative impacts to reefs
Salt Intrusion – SLR may cause salt intrusion into aquatic ecosystems, wetlands, low-land agriculture, and coastal plain groundwater systems.
Drainage Problems – SLR may raise the groundwater table leading to increased flooding, poor drainage, and storm damage where rainfall and high ocean levels converge.
Too much water in some areas will be met by too much heat in others. As the report notes about this year's drought in the US:
The 2012 drought in theUnited States impacted about 80 percent of agricultural land.
That is what prompted my earlier post about 104
o F. Now we need to focus people on the need to AVOID a 4
o C. increase. If that doesn't sound like much consider this scenario:
The average temperature of humans is 98.6o F. A 4o C. (7.2o F.) increase would be a temperature of almost 106o F. That's not something you adapt to.
If that makes you thirsty just thinking about it, you will be unhappy to know that increasing temperatures will also deplete potable water supplies. The old adage of "fives" come to mind.
Five weeks without food
Five days without water
Five minutes without air.
We already fight wars for oil, which we could survive without, albeit in a radically different world. If we don't take this seriously now, what makes you think we won't be fighting for water in the near future as the world bakes around us?