One of the biggest challenges in dealing with the Climate Crisis future is the complexity. It is a future that must be anticipated to be addressed, yet the factors involved and their interactions are more complex than anything humanity has been forced to face. This truly is the test of our evolution, in both the strict Darwinian sense and in the more common sense of "evolved," meaning that if we've gotten better, more able, more developed as a species, then this will be the proof.
The future is always a kind of fiction, because by definition it has not yet happened. So scientists adopted the language of drama in developing "scenarios" which they constructed using mathematical tools of forecasting and projecting, and the mathematically-based models they develop. The IPCC fourth assessment was able to apply more precise measurements, more ingeniously developed data and refined models, tested by their ability to "predict" the past.
The assessment is not the only set of projections and models out there that bear upon the Climate Crisis future. Some say it is among the most conservative. But even with all the data, all the attention, all the models, the various scenarios of the future are still frustratingly sketchy, at least as far as I can determine from my small researches. That's partly because of the nature of climate science, the nature of the future, and the unprecedented need and nature of what we're dealing with. But it may be that someone can construct some kind of timeline, pretty soon.
What do we think we know? Climate scientists have been measuring what's been happening, especially in the past decade, when the global temperature has been noticeably rising, with noticeable effects: longer and more intense heatwaves in Europe and much of North America, for example; the heating of the Arctic and melting of ice at both poles; the first signs of effects on wildlife and vegetation, and the first signs of new patterns of disease.
What does the future hold and when? The keys are how high the temperature rises, and how much of the greenhouse gases are in the atmosphere. Out of the facts and informed speculations, there are some dates and forecasts that stand out.
The IPCC assessment summary forecasts for the 21st century, and says that "Warmer and fewer cold days and nights" and "warmer and more frequent hot days and nights over most land areas" are "virtually certain," while more frequent heat waves and heavy precipitation are "very likely" and an increase in areas affected by droughts, an increase in intense tropical cyclones, and increased incidence of extreme high sea levels are "more likely than not."
According to news accounts, a draft for a IPCC report that will be issued later is more precise about effects and time: "The report estimates that between 1.1 billion and 3.2 billion people will be suffering from water scarcity problems by 2080 and between 200 million and 600 million more people will be going hungry."
The Stern Report in England, which focused on economic impacts, had this to say:
"Climate change threatens the basic elements of life for people around the world – access to water, food, health, and use of land and the environment. On current trends, average global temperatures could rise by 2 - 3°C within the next fifty years or so,1 leading to many severe impacts, often mediated by water, including more frequent droughts and floods.
• Melting glaciers will increase flood risk during the wet season and strongly reduce dry-season water supplies to one-sixth of the world’s population, predominantly in the Indian sub-continent, parts of China, and the Andes in South America.
• Declining crop yields, especially in Africa, are likely to leave hundreds of millions without the ability to produce or purchase sufficient food - particularly if the carbon fertilisation effect is weaker than previously thought, as some recent studies suggest. At mid to high latitudes, crop yields may increase for moderate temperature rises (2 – 3°C), but then decline with greater amounts of warming.
• Ocean acidification, a direct result of rising carbon dioxide levels, will have major effects on marine ecosystems, with possible adverse consequences on fish stocks.
• Rising sea levels will result in tens to hundreds of millions more people flooded each year with a warming of 3 or 4°C. There will be serious risks and increasing pressures for coastal protection in South East Asia (Bangladesh and Vietnam), small islands in the Caribbean and the Pacific, and large coastal cities, such as Tokyo, Shanghai, Hong Kong, Mumbai, Calcutta, Karachi, Buenos Aires, St Petersburg, New York, Miami and London.
• Climate change will increase worldwide deaths from malnutrition and heat stress. Vector-borne diseases such as malaria and dengue fever could become more widespread if effective control measures are not in place. In higher latitudes, cold-related deaths will decrease.
• By the middle of the century, 200 million more people may become permanently displaced due to rising sea levels, heavier floods, and more intense droughts, according to one estimate.
• Ecosystems will be particularly vulnerable to climate change, with one study estimating that around 15 – 40% of species face extinction with 2°C of warming. Strong drying over the Amazon, as predicted by some climate models, would result in dieback of the forest with the highest biodiversity on the planet.
The consequences of climate change will become disproportionately more damaging with increased warming. Higher temperatures will increase the chance of triggering abrupt and large-scale changes that lead to regional disruption, migration and conflict.
• Warming may induce sudden shifts in regional weather patterns like the monsoons or the El Niño. Such changes would have severe consequences for water availability and flooding in tropical regions and threaten the livelihoods of billions.
• Melting or collapse of ice sheets would raise sea levels and eventually threaten at least 4 million Km2 of land, which today is home to 5% of the world’s population. "
In a recent speech, NASA climate expert James Hansen said this:
Global warming of 2-3°C will occur if we follow business-as-usual, we are sure, because the sensitivity of climate is well-constrained by its history. Such a scenario threatens even greater calamity, because it could unleash positive feedbacks such as melting of frozen methane in the Arctic, as occurred 55 million years ago, when more than 90% of species on Earth went extinct. An alternative scenario, with additional warming less than 1°C is possible, but it requires that CO2 emissions decrease about 25%by mid-century and about 75% by the end of century.
So what can we say about the Climate Crisis future, just based on these findings of probabilities, possibilities, contingencies and projected effects? A great deal, actually, even though this is very incomplete, and requires explanation, extrapolation and details of alternate scenarios.
Here is my basic understanding of what we're talking about, and the basis for my speculations to come: we are in a Climate Crisis, and we will be living in its effects for the rest of our lives. For the next few years, depending on where we live, we will experience unusual weather and longer term effects of new climate trends, such as the dying of certain tree species that New Englanders are already noticing, new wildlife patterns, including insects that may bring diseases to new areas. There will be definite impacts of storms and floods and dry seasons.
Other effects will be cumulative. The strain on medical and social systems as cities experience more frequent killer heat waves, for instance. Or drought, as parts of the U.S. and Africa are already experiencing. And the effects of melting and higher temperatures in near-Arctic regions, with cumulative effects on fish and animals, already noticeable in areas where the ecology is very delicate. And the changes in growing seasons, migration patterns and so on that go with a shift in when seasons begin and end, and their different character. All this changes daily life and a lot more. Things that seemed forever--like the weather that keeps California wineries in business--may fade relatively quickly, with all the economic and social effects and upsets.
Whatever effects we will have, we will have them for the next three decades no matter what we do to control new greenhouse gas emissions. Further, the IPCC suggests that the rate of rise in temperature will increase every decade. There will be variations from year to year perhaps, but the planet will be on average hotter than it was the previous decade. So we ain't seen nothing yet.
If we do control those emissions and otherwise address the causes of the crisis, we may avoid the starving billions in 2080, and the end of life as we know it on the planet beyond this century. But we won't avoid everything--some effects will be with us for a thousand years, the IPCC says. And even if we avoid billions going hungry and thirsty, we still may have millions, perhaps even well before 2080. And that's from the direct effects of climate--not including how humanity will react. Some say that part of the future is being forecast by what's happening in Darfur.
So what does all that mean for public awareness and public policy? To be continued.
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