by Will Boisvert
How bad will climate change be? Not very.
No, this isn’t a denialist screed. Human greenhouse emissions will warm the planet, raise the seas and derange the weather, and the resulting heat, flood and drought will be cataclysmic.
Cataclysmic—but not apocalyptic. While the climate upheaval will be large, the consequences for human well-being will be small. Looked at in the broader context of economic development, climate change will barely slow our progress in the effort to raise living standards.
To see why, consider a 2016 Newsweek headline that announced “Climate change could cause half a million deaths in 2050 due to reduced food availability.” The story described a Lancet study, “Global and regional health effects of future food production under climate change,”  that made dire forecasts: by 2050 the effects of climate change on agriculture will shrink the amount of food people eat, especially fruits and vegetables, enough to cause 529,000 deaths each year from malnutrition and related diseases. The report added grim specifics to the familiar picture of a world made hot, hungry, and barren by the coming greenhouse apocalypse.
But buried beneath the gloomy headlines was a curious detail: the study also predicts that in 2050 the world will be better fed than ever before. The “reduced food availability” is only relative to a 2050 baseline when food will be more abundant than now thanks to advances in agricultural productivity that will dwarf the effects of climate change. Those advances on their own will raise per-capita food availability to 3,107 kilocalories per day; climate change could shave that to 3,008 kilocalories, but that’s still substantially higher than the benchmarked 2010 level of 2,817 kilocalories—and for a much larger global population. Per-capita fruit and vegetable consumption, the study estimated, will rise by 6.1 percent and meat consumption by 5.4 percent. The poorest countries will benefit most, with food availability rising 14 percent in Africa and Southeast Asia. Even after subtracting the 529,000 lives theoretically lost to climate change, the study estimates that improved diets will save a net 1,348,000 lives per year in 2050.
A headline like “Despite climate change, rising food production will save millions of lives” isn’t great click-bait, but it would give a truer picture of a future under global warming as envisioned in the Lancet study. That picture is typical of the scientific literature on the impacts of climate change on human welfare. Global warming won’t wipe us out or even stall our progress, it will just marginally slow ordinary economic development that will still outpace the negative effects of warming and make life steadily better in the future, under every climate scenario. What the doomsday prognostications of drought and flood, heat-stroke and famine, migration and war miss is that climate change is not the only thing going on in the world, or even the most important thing.
It’s not even a new thing. Throughout history humans not only weathered climate crises but deliberately flung ourselves into them as we migrated away from our African homeland into deserts, mountains, floodplains and taiga. Global warming pales beside the climatic challenge surmounted by the Inuit when they settled the Arctic with igloos and kayaks, revolutionary technologies that improved their ability to travel and hunt. Theirs is just one example of the human capacity for finding better ways to get food, shelter, energy and resources from the hostile environments we embrace. “Adaptation” is not quite the right word for that process, which is so ubiquitous—and so fundamental to progress—that it is the essence of development.
This latest episode in humanity’s ongoing conquest of extreme climates will likewise amount to just another problem in economic and technological development, and a middling-scale one at that. Although clean energy will play a significant role by slowing and perhaps moderating global warming (as well as reducing pollution and easing resource constraints), contrary to the decarbonize-or-die doomsayers our main response to climate change will be other kinds of development that make climate change irrelevant. We will grow more food, harness more water, cool ourselves more vigorously, move to new lands and build—and-rebuild—new cities. We will exploit technological breakthroughs, but mostly we will improve familiar technologies and deploy them more widely. We will do all this not because of global warming but because of more pressing challenges like population growth and the demand for higher living standards. The means by which we will overcome specific problems posed by climate change look less like the pristine “sustainable development” envisioned by greens and more like the ordinary development that has always sustained us.
The conquest of drought
Environmentalists cite the 2006-10 drought in Syria, often credited with sparking the civil war there, as an omen of the crises climate change will bring.  But the drought also hit Israel, and the effect there was altogether different. Shortages forced Israel to tighten its already stringent water conservation and recycling standards. More importantly, they prompted breakthroughs in reverse-osmosis desalination technology, cutting by half the energy needed to extract fresh water from the sea and dramatically lowering the cost to just 58 cents per cubic meter (1,000 liters) of drinkable water.  As a result, Israel’s water situation U-turned from worsening scarcity to sufficiency. The arid country now desalinates 600 million cubic meters of water annually, easing the pressure on natural freshwater sources like the Sea of Galilee. More desal plants are being built. By 2020 Israel will get at least 40 percent of its water, including irrigation water, from desalination. 
The implications of cheap desalination are profound. By tapping limitless sea-water resources it could drought-proof agriculture and thus eliminate the greatest threat posed by climate change. The recent mega-drought in California prompted much climate alarmism, but at the low prices achieved in Israel the state could generate its entire annual water consumption of 40 million acre-feet from desal plants for $30 billion a year, just 1.2 percent of the state’s GDP.  It won’t come to that: freshwater sources will never completely dry up and desal at $715 per acre-foot would still be several times more expensive than natural water in California (though not during droughts, when auction prices for irrigation water can spike as high as $2,200 per acre-foot).  Still, if Californians had to rely on desal they could do it without breaking a sweat. Contrary to the Blade Runner franchise, Californians in 2049 will live off of well-watered produce fields, not desiccated grub farms.
The world’s driest regions will increasingly rely on desalinated water for drinking and farming, but less splashy technologies will dominate water supply. Efficiency measures like drip irrigation (invented in Israel) and recycling (86 percent of the water Israeli households use gets recycled for irrigation)  will stretch existing water sources much further. Efficiency has already let the developed world turn the corner on water consumption: America’s total water withdrawals in 2015 were 13 percent below the 1980 peak, for a much larger population and economy. 
Simply moving water where it’s needed will continue as the mainstay of water management. Here California is the leader. The California Aqueduct, running 400 miles up and down mountain ranges to take water from the wetter north to the drier south, is just part of a colossal irrigation system that has made the state’s arid landscape an agricultural powerhouse. Since ancient Sumeria’s hey-day water infrastructure has been humanity’s most important development strategy and climate technology; we will continue to expand it, on continental scales, to even out erratic rainfall and conjure fertile fields from bone-dry weather.
The examples of Israel and California show that developed countries will never face serious water shortages in a warming climate. Spreading water security to the rest of the world will thus depend not on decarbonization but on development of a very basic kind: dams, canals and pipelines; sewage treatment and recycling plants; low-flow shower heads and irrigation sprinklers; a backstop of desalination plants. Investments in these technologies and infrastructures, new and old, will resolve problems of drought and aridity that have bedeviled us since civilization began—and eliminate the worst risk of climate change in passing.
The conquest of hunger
Steadily improving water supplies will shore up our food supply, but other advances—from genetically modified seeds to innovative tilling to better storage facilities—will have a huge impact too, ensuring that farm productivity soars on a warmer planet.
Warming by itself will likely have only modest effects on farm productivity, according to projections from the International Panel on Climate Change.  The IPCC assessed changes in the yields of the major grain crops under warming of up to 5 degrees Celsius—a worst-case scenario, far beyond the 2-degree threshold of doom cited by policy-makers—and the results are decidedly un-alarming. In temperate regions climate change would cause yields of corn and wheat to decline by about 10 percent and rice yields by 15 percent. However, all these declines could be reversed by adaptations like earlier planting dates: with adaptation temperate-zone corn and rice yields would not decline at all and wheat yields would rise 9 percent. Tropical areas could see corn yields decline about 15 percent and rice yields 7 percent, but with adaptation tropical rice yields would instead rise 12 percent. Tropical-zone wheat yields would suffer a serious decline of over 30 percent even with adaptation, but farmers don’t grow much wheat in the tropics so the effect on global supply would be small.
These limited and mostly reversible effects of climate change barely register beside the real challenge facing agriculture—the steeply rising demand for food. By 2050 an extra 2 billion mouths to feed and meat-heavier diets will make global food consumption swell by 50 to 100 percent over the 2006 level.  Compared to population growth, richer diets and the imperative to reduce hunger in impoverished nations, global warming will be a minor burden; decarbonizing the energy supply would thus do little to reduce the stress on food supplies. Some decarbonization measures, like the diversion of food crops to produce low-carbon biofuels, will actually worsen the food crisis. One study estimates that by 2050 biofuel production will consume up to 363 million tons of crops, the equivalent of 14 percent of 2017’s global cereal-grain harvest.  If we simply drop biofuels from clean-energy policy, that alone would erase most of the projected food deficit caused by climate change.
Meanwhile, countervailing developments that increase yields will outrun the effects of climate change and dramatically raise farm output. They’re already working; in the past ten years the global grain harvest grew 23 percent, half again as much as the 15 percent growth in population.  Productivity will keep rising. A recent report from the International Food Policy Research Institute spotlighted a range of innovations that will boost yields: better weed treatments can raise corn, rice and wheat yields by 6 to 12 percent; heat-tolerant crop varieties can raise corn yields by 31 to 37 percent and wheat yields by 16 to 28 percent; no-till cultivation can raise corn yields 20 to 67 percent and wheat yields 19 to 57 percent.  Advanced technologies like genetically engineered seeds will play a role, but basic inputs will be more important: a recent study in Nature estimated that simply using more irrigation and fertilizer could raise yields 45 to 70 percent. 
Developing countries will see the greatest productivity gains—Africa could more than double its grain harvest by bringing yields up to the current global average —but Western agribusiness will continue to improve as well. Comparing three-year averages in the U. S. in 2014-2016 with the 2004-2006 period, corn yields grew 12 percent over the decade, wheat yields 13 percent and soybean yields 15 percent.  There’s still plenty of room for improvement by adopting best practices: winners of the 2016 National Wheat Yield Contest beat their counties’ average yields by anywhere from 37 to 377 percent.  Farmers will also expand production by cultivating new land in vast northern regions where warming will improve the climate. In Canada rising temperatures could boost corn yields 60 percent and wheat yields 70 percent. 
We will also get more food by not wasting it. The world currently wastes about one third of the food it produces.  In developed countries much of it is rejected by finicky retailers and shoppers or left to molder in the fridge, but in poor countries it is mostly lost in pre-marketing stages—rotting in fields or spoiling after harvest before it reaches market. Africa could recover about 11 percent of its food supply by reducing losses in production, storage and distribution to European levels. The technology is banal: machinery that can harvest fields quickly when destructive weather threatens; plastic bags and metal silos to keep insects out of grain; roads and trucks to take produce quickly to market, plastic crates to keep it from getting crushed en route, refrigerated warehouses to keep it fresh and canneries to preserve it. 
Global warming won’t crimp the world’s food supply much and decarbonization won’t safeguard it. Preserving and expanding the food supply to meet rising demand will rely on hum-drum investment in growing and processing food—doing what we do now, only more and better. Unfortunately, misplaced environmental priorities may undermine that program by demonizing important technologies like GMOs and championing organic farming and other low-input, low-yield models as replacements for industrial agriculture. To feed the world we will have to question that vision of sustainability.
The conquest of heat
The most lurid climate change scenario is the wet-bulb apocalypse: the combination of rising temperatures with humidity so saturating that sweat cannot evaporate from the skin to cool the body. In a recent climate jeremiad in New York Magazine David Wallace-Wells claims that global warming will make such steam-bath weather so commonplace that outdoor work would become impossible in many places. Eventually, he warns, “more than half the world’s population, as distributed today, would die of direct heat.” 
But contrary to Wallace-Wells’s panic, extreme heat is becoming quite livable thanks to another banal technology: air conditioning. Just as people in the past used fire and clothing to settle in lethally cold climates, today we are using cheap cooling technology to expand into lethally hot climates with no harm to our health. Thanks to air conditioning the Florida-to-Nevada swelter-belt has seen a population boom—disproportionately of heat-vulnerable retirees—at the same time as annual heat-related deaths in the U. S. have plunged 80 percent.  Mechanical cooling made the furnace-city of Dubai, where average high temperatures top 100 degrees Fahrenheit six months a year, into an international business hub as its population exploded from 40,000 to 2.5 million. 
Mass cooling is gathering steam in developing countries, where air conditioners are now one of the first electric appliances people buy. Urban Chinese have installed 200 million room air conditioners in the last 15 years, and there is now one air conditioner for every Chinese home.  A recent study estimated that the world will install another 700 million new AC units by 2030, and a further 900 million between 2030 and 2050.  Soon the world will consider an air-conditioned home to be as rudimentary an aspect of human comfort as a warm hearth on a cold night.
In time the cooling bubble will become portable enough for heavy outdoor labor. American farmers already work their fields in the comfort of air-conditioned combine cabs; less mechanized farms could set up battery-powered tents with AC and cold water to cool over-heated laborers. Qatar is experimenting with solar-powered hats that waft cool air over construction workers.  The ultimate response to unhealthy working temperatures may be to automate outdoor work. Farm robots can already pick apples and strawberries, thin lettuce seedlings, milk cows and grow barley from plowing through harvest.  The idea that we have to moderate the climate to make manual field labor more bearable gets development priorities backwards; the worse failure will be if, a hundred years from now, humans still do that back-breaking work.
For billions of people life is already too hot, so the artificial cooling of humanity will proceed regardless of climate change or decarbonization goals. A key part of that will be supplying electricity to run (and build) air conditioners; India’s soaring AC demand will necessitate some 300 new power plants over the next two decades.  Here too there’s a tension between necessary development and green sustainability doctrine, with its emphasis on reducing energy use and relying on intermittent wind and solar generators. Cooling requires a lot of electricity that is reliably available when demand is greatest; given the limitations of wind and solar, much of that electricity will have to come from new nuclear and, for now, fossil-fueled plants. High-quality power will take precedence over intermittent energy austerity as a strategy for beating the heat.
Sea-level rise is the most unsettling aspect of global warming. Major coastal areas and many large cities will be inundated; some of that is already baked into current carbon dioxide levels, with the only question being how many centuries it will take. The prospect threatens the loss of homes, of unique urban and regional cultures, and of our sense of the permanence and meaning of our world.
But as apocalyptic as it seems, sea-rise poses little risk to human well-being. The destruction will be real, and wrenching, but not overwhelming or even unusual. It will necessitate abandonment and migration and rebuilding—but such upheavals are so deeply woven into modern life, on such a grand scale, that the increment caused by climate change will hardly break our stride.
As with agriculture, climate change ranks far down the list of challenges to our built environment, infrastructure and living space. Serious problems will emerge towards the end of this century, when waters could rise up to 2 meters  and require major investments in sea-walls and flood-control infrastructure. More flooding will ensue, with estimates putting the number of people who could ultimately be displaced at anywhere from 72 million to 750 million over several centuries.  By any measure, involuntary migration of hundreds of millions of people to higher ground ranks as a cataclysm. But it’s nowhere near as cataclysmic as ordinary population growth, which will force the world to find room, homes and infrastructure for an extra two billion people by 2050.
To see what that much larger non-climatic upheaval will be like over the next 33 years we need only look at the last 33 years, during which the world gained almost three billion extra inhabitants. Those decades were a time not only of colossal population growth but of epic migrations, primarily internal migrations that often go unremarked. In China, 170 million peasants left their villages and moved dozens to hundreds of miles into cities after 1979,  while in India there are currently 450 million internal migrants.  The tidal wave of population growth and migration necessitated a frenzy of city-building. China’s Shenzhen takes the prize for growth, with its population exploding from 30,000 in 1979 to over 10 million today. Comparable growth took place in megacities the world over, from the Indian technology hub of Bangalore, which added over five million people after 1981, to metropolitan Phoenix, where migrant-driven urbanization tripled the population to 4.6 million.  Yet despite the strain of new people and vast relocations, far exceeding anything that climate change will cause, the period since 1980 has been a golden age of development that lifted billions of people out of deep poverty.
Break-neck construction to keep up with giant dislocations isn’t a rupture with modern life but the essence of modern life, and modernity has navigated far more extreme episodes than climate change promises. Germany and Japan emerged from World War II destitute and with their cities destroyed, but within a few decades they had rebuilt themselves from the ground up better than before. Slowly rising seas won’t pose anything like a comparable task of reconstruction.
And while the sheer waste of abandoning the wealth and labor embodied in coastal cities feels appalling, it seems less so when we reflect on just how new, provisional and even disposable our material civilization really is. In 1820 New York held just 152,000 people crammed into a tiny footprint.  Almost everything in the city of 8 million—tenements, skyscrapers, bridges, subways, docks, airports, the Bronx—was built in 200 years, and much of it demolished and rebuilt several times over in search of higher rents. The task of constructing a New New York somewhere inland over the next 200 years as the old one drowns seems gargantuan, but that was exactly the project the city embarked on in 1820 under horse-power and candle-light.
Rebuilding is an aspect of economic development that humans do quite well. We built the whole world in the last two centuries—much of it in the last two generations—and rebuilding a waterlogged fraction of it over the next two centuries, with the help of incomparably better technology, will hardly tax us.
The most inexorable feature of climate-change modeling isn’t the advance of the sea but the steady economic growth that will make life better despite global warming.
The consensus of economic forecasts in IPCC reports and elsewhere is that climate change will make only modest inroads into growth rates,  leaving plenty of growth to accommodate development, new infrastructure (including adaptations to climate change) and rising standards of living.  One study estimates that by 2100 the world will be spending up to $71 billion a year on sea walls to protect coastal areas—a huge sum, but only a drop in the bucket compared to a global GDP estimated to grow to at least $355 trillion by then.  Economic models of global warming are virtually unanimous in predicting at least a doubling of global per-capita GDP by 2100. 
The main threat to economies won’t be global warming, but the age-old problems of bad economic policy and bad governance. Venezuela’s collapse, complete with spiraling hunger and violence, outdoes anything we can expect from climate change. Climate crises are symptoms, not causes, of failed states. Blaming the turmoil in Syria on warming-induced drought gets the equation backwards: it’s the country’s deranged political culture, corrupt and authoritarian government, and persistent underdevelopment that turned drought into a precipitating factor for civil war. Because Israel is a liberal democracy with an accountable government focused on development, it responded to the same drought with transformative technology. Political reform is perhaps the most important development initiative of all.
The conquest of carbon?
The effects of climate change on human welfare will be modest in comparison to other economic and social challenges, and they will be more than compensated by ongoing development in water management, agriculture, cooling and infrastructure. Green doctrine and sustainability policy, however, have fixated on just one aspect of development: renewable energy.
That focus has brought positive results in the form of falling prices and accelerating deployment of wind and solar power, which are beginning to slow the growth of fossil-fueled electricity. If that trend strengthens it could mitigate warming and help moderate worst-case scenarios, as well as abating air pollution from fossil fuels. Economic modeling generally shows that investments in low-carbon energy are cost-effective in the long run.
Unfortunately, renewables are still growing too slowly to have much effect on greenhouse emissions. The portion of global electricity generated from low-carbon sources, nuclear and renewable, fell from 35.2 percent in 2000 to 33.5 percent in 2015. That relative decline has reversed itself in recent years, with the low-carbon fraction growing slightly to 34.2 percent in 2016;  but that progress is still far too slow to meet decarbonization deadlines. Worse, comprehensive decarbonization with the favored technologies of wind and solar will likely prove impossible; fossil fuels will remain necessary on a large scale to balance their surge-and-slump intermittent power. Even if renewables could somehow supply all our electricity, major greenhouse emissions from manufacturing and agriculture would persist.
The sluggish pace of decarbonization will drag on for the foreseeable future. Difficulties in integrating chaotic wind and solar generators have already slowed deployments in some countries. Renewable-energy supports have been cut back in recent years, not only in the United States but in the United Kingdom, Germany, Spain and Australia. A Nature editorial on the Paris Agreement noted that “no major advanced industrialized country is on track to meet its pledges” to control greenhouse emissions.  Political pressure for more vigorous decarbonization will stay weak. The much-celebrated boom in renewable capacity also breeds complacency by suggesting to the public that the greenhouse problem is being solved even though it isn’t. Until rising seas become noticeable late in the century, global warming will present few tangible harms that could galvanize climate politics.
In the green movement itself the push for clean energy has been hobbled by the self-contradictory politics of fear that drive it. Global-warming activists have captured the public imagination with their warnings of an existential threat to the planet. Unfortunately, the same catastrophist mindset has anathematized technologies that would ease decarbonization. Anti-fracking movements would make gas-fired electricity, indispensable for balancing wind and solar, scarcer and more expensive than it needs to be. The green jihad against nuclear power, a safe and generally cheap source of reliable low-carbon energy, is especially counterproductive. Greens, motivated by outlandish exaggerations of the risk of nuclear accidents, have forced governments in Germany, Japan and elsewhere to shut down emissions-free reactors while leaving coal-fired plants in service. The apocalyptic tone that now dominates environmental discourse on every issue not only overstates the threat of warming, it gives us incoherent climate and energy policies that make warming worse.
Behind the feckless performance of clean-energy policy lies a simple reality: low-carbon power is just not critical to our well-being. Worse, pursuing it sometimes conflicts with our demand for reliable energy to run air conditioners, tractors, fertilizer plants, water pumps, steel mills, factories and construction sites. Because they address pressing needs and aren’t subject to the collective action problems that plague global climate policy, these kinds of development will take precedence over clean energy. Greens often decry these priorities as short-sighted, but in fact they address the concrete risks of hunger, heat and dislocation that climate change poses more directly than the slow, politically muddled strategy of decarbonization.
The conquest of fear
We have come to think of climate change as the canonical “extinction-level event,” a catastrophe so multifaceted and all-encompassing that it puts human survival in doubt. But when we think harder about the specific problems global warming poses—problems of water management, agricultural productivity, cooling and construction—the threat becomes less daunting. Our logistic and technical capacities are burgeoning, and they give us ample means of addressing these problems.
Moreover, the scope of warming issues, even under worst-case scenarios, is modest compared to the task of feeding and housing several billion extra people over the next few decades and accommodating the higher living standards that impoverished countries demand. That “development crisis” dwarfs the climate crisis, yet we don’t think of it as a crisis because we are steadily (though too slowly) resolving it and will continue to do so in the future. Along the way, we will resolve the climate crisis, which is fundamentally the same thing as the development crisis. Pre-modern Europe endured many climate crises—famines caused by inclement weather lasting a season or a century—that subsided with modern development; our contemporary warming issues are also symptoms of lingering underdevelopment. The faster we develop, the faster we resolve the climate crisis by decoupling our well-being from the weather.
Global warming will have serious consequences that need to be reckoned with. Cleaning up the energy supply is an important—and accelerating—aspect of development that should be nurtured, but it must be balanced against more pressing needs that sometimes conflict with it. To get the balance right greens need to give up their anxiety over development and over technologies like nuclear power that can make development both faster and cleaner. Like the man said, freedom from fear is the greatest liberation of all.
- https://www.technologyreview.com/s/534996/megascale-desalination/ , https://www.scientificamerican.com/article/israel-proves-the-desalination-era-is-here/
- 1233 cubic meters per acre-foot times $0.58 per cubic meter times 40,000,000 acre-feet. California’s 2015 GDP was $2.46 trillion, http://www.realclearmarkets.com/articles/2016/07/14/is_california_really_the_6th_largest_economy_in_the_world_102263.html
- California’s irrigation water cost about $120 per acre-foot before the drought https://www.cnbc.com/2016/08/15/california-drought-costs-to-top-600-million-dollars.html , auction spikes of up to $2,200 per acre-foot http://www.mercurynews.com/2014/07/19/california-drought-high-bidding-farmers-battle-in-water-auctions/
- https://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap7_FINAL.pdf p. 498, percentages by eyeball.
- 49 percent increase in food demand by 2050, http://www.sciencedirect.com/science/article/pii/S0378429012001876 , doubling of food demand by 2050 http://www.nature.com/nature/journal/v490/n7419/full/nature11420.html
- 163-363 million tons diverted to bio-energy, http://www.sciencedirect.com/science/article/pii/S0378429012001876 , harvest forecast to be 2,613 million metric tons in 2017-18 http://www.fao.org/worldfoodsituation/csdb/en/
- Harvest growing 23 percent http://www.fao.org/worldfoodsituation/csdb/en/ World population grew from 6.6 billion in 2007 http://www.prb.org/Publications/Datasheets/2007/2007WorldPopulationDataSheet.aspx to 7.6 billion in 2017 http://www.worldometers.info/world-population/
- http://www.fao.org/3/a-i4691e.pdf , p.31.
- http://staging.unep.org/wed/2013/docs/WRI-UNEP-Reducing-Food-Loss-and-Waste.pdf Africa could recover about 11 percent of the food lost to waste, numbers from Table 6.
- Pick apples https://www.nanalyze.com/2017/05/6-agriculture-robot-startups-farming/ ; strawberries and lettuce https://gizmodo.com/13-fascinating-farming-robots-that-will-feed-our-future-1683489468 ; milk cows http://robohub.org/farming-with-robots/ ; barley https://www.engadget.com/2017/09/07/farm-robot-harvest-hands-free-hectare/
- 72 million https://www.huffingtonpost.com/elliott-negin/think-todays-refugee-cris_b_7691330.html 750 million http://sealevel.climatecentral.org/news/global-mapping-choices
- https://en.wikipedia.org/wiki/Shenzhen https://en.wikipedia.org/wiki/Bangalore https://en.wikipedia.org/wiki/Phoenix_metropolitan_area
- https://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap10_FINAL.pdf , p. 691.
- https://www.nature.com/articles/nclimate2481 https://images.nature.com/original/nature-assets/nclimate/journal/v5/n2/extref/nclimate2481-s1.pdf
- BP Statistical Review of World Energy 2017, underpinning data, https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy/downloads.html