One of the biggest failures in climate change reporting is the tendency to focus on particular aspects without considering the bigger picture. What does sea level rise have to do with droughts or floods? What is the role of changing ocean circulation patterns? How do these impacts all factor into our rapidly changing jet stream?
When we look at individual aspects we usually wind up with charts that reveal a linear pattern. Sure, there may be dramatic increases on the curve, but nothing that appears wild or unpredictable.
Yet we're nearing the point where climate change impacts will be wild and unpredictable, totally non-linear. A big part of this results from the "cascade effect" in which a number of seemingly unrelated impacts begin operating together, even harnessing man-made change with natural feedback mechanisms that will be much harder to control and nearly impossible to reverse. We can expect to be overtaken by fast-developing events and very possibly without adaptation strategies or preparations. In the scope of climate change, it's like we've all but given up.
An online course being presented by Germany's prestigious Potsdam Institute provides the missing link. It begins to connect all the dots to reveal how changes already underway that will continue to accelerate and worsen even if we miraculously decarbonize today to make our world a far more difficult place for almost all forms of life.
One example is the Greenland ice sheet. As it melts, the cold freshwater released to the sea has a direct impact on the thermohalene circulation (Gulf Stream) which, in turn, speeds up the decline in the Arctic sea ice and the thawing of high latitude permafrost and the loss of Alpine glaciers.
As the Arctic warms the temperature differential between the Arctic and temperate latitudes narrows, weakening the jet stream and giving rise to Rossby waves, blocking events that can stall weather fronts in a particular location for upwards of four weeks. These Rossby waves are responsible for Atlanta, Georgia falling into a February deep freeze while a village in Alaska hits temps. in the 60s. These Rossby waves created the conditions for the Calgary flood and triggered the recent drought in Russia that ruined the wheat harvest there.
The Amazon rainforest governs precipitation patterns in much of South America. A warming beyond 2C carries the risk of transforming the Amazon into savannah grasslands, upending essential rainfall needed for many millions of Brazilians and their neighbours.
The hydrologic cycle is the climate change cycle. Our civilization is utterly dependent on the steady and predictable supply of precipitation for human needs (drinking, cooking, sanitation), for agricultural production and for industry. When precipitation falters and becomes unreliable or sporadic, there goes your economy and, with it, your civilization. This is nothing new. We have a rich history of this sort of societal collapse.
Already billions lack adequate access to safe water. Billions do not have access to basic sanitation. Even as we experience growing water scarcity many of the most vulnerable countries also heavily contaminate their freshwater resources. This is compounded by deteriorating ecosystems and by failing infrastructure and lack of investment. Water is something we're all too ready to fight over when scarcity sets in and there are few coherent international policies to deal with conflict.
Two areas expected to be among the hardest hit are Africa and Asia. They're also experiencing explosive population growth. They're going to be especially vulnerable to droughts, floods and sea level rise. It's estimated the world will need to up food production by 50-70% by 2050 to keep up with the growing population yet these climate change impacts, taken cumulatively, will cause a sharp decline in food production in the most needy areas. Draw your own conclusions as to how that will play out especially in the Hindu Kush.
Our ecosystems are in a migratory transition. Plants and animals alike are responding to climate change by steadily moving away from the equator. Although you may think otherwise in central and eastern Canada, Spring is now arriving two weeks earlier globally. Pests and disease are also migrating. West Nile virus is one example. Above 2C be prepared for a spread of malaria and a sharp increase in infections. As it warms the incubation period for malaria plummets and mosquitoes bite a lot more. Water-related diseases from cholera to typhus to dysentery also increase.
It's critical to consider the effect this warming already underway will have on biodiversity. Many species are incapable of evolving to survive the current, early onset, rate of change. If we fail to arrest global warming at 2C (now considered highly unlikely) and instead allow it to reach 4C, the number of species lost will skyrocket. 2C simply gives many species a window to survive through adaptation, evolution migration.
This week it was announced that, in March, we set another record when every part of the planet experienced GHG concentrations about 400 ppm. Everywhere. To put that in perspective, our coral reefs cannot survive long beyond 350 ppm. of atmospheric CO2. It's calculated that 1.5C of warming will kill off all but 10% of the world's corals. Here's the thing. It was recently reported that our existing emissions, what we've already put into the atmosphere, will "lock in" 1.5C of warming by 2100. We've already pulled the Celsius trigger. Now we've pulled the acidification trigger. Sea level rise stresses corals. So do severe storm events such as the cyclones savaging the central western Pacific.
As I went through the lectures from these top world scientists, leaders in their own disciplines, in looking to what awaits in a 4C world each said the same thing - "all bets are off." Each of them described their field in the context of a climate change impacts "cascade" but noted that these combined impacts and they synergies are beyond anything in the experience of human and other life forms. Most also pointed out that, by the time we get to understand the cascade fallout, it'll be too late to do anything about it.
To sum up, we've got two choices - just the two. Either decarbonize now, just as quickly as humanly possible, or "don't worry, be happy."