Excerpt From: Rischard, Jean-Francois.
“High Noon: 20 Global Problems, 20 Years To Solve Them.” iBooks.
“Global warming (or climate change as it is also often referred to) is rapidly emerging as one of the toughest and most threatening of the twenty or so inherently global issues. This issue is so big, so much in the limelight, that I will spend more time on it than on the others in this chapter.
The world’s climate has never been static. Over the past 4.5 billion years, it has shifted constantly due to volcanic emissions, tectonic plate movements, changes in solar radiation, and several other factors. Yet, since the last ice age, the earth’s climate has been relatively stable, with global temperatures varying by less than 1°C over a century in the last 10,000 years. But there is more and more evidence that human activities over the last 100 years have started to play a major role in producing rising temperature levels, with a worrisome acceleration over the last twenty years.
What’s behind all this? Once solar heat reaches the earth, part of it gets absorbed by the atmosphere above us. Of the balance that hits the surface, some gets absorbed by the ground and the oceans and some bounces back. Of that bounce-back part some escapes back into space, but some gets trapped by certain gases in the atmosphere that are forming a layer around the earth—very much as heat gets trapped inside a greenhouse. Global warming occurs when this trapping increases as a result of rising concentrations of these gases, now known as greenhouse gases:
Carbon dioxide, emitted mostly as a result of burning fossil fuels, such as oil, gas, and coal, and also as a result of deforestation.
Methane, mostly from cattle and rice farming and from landfill waste.
Nitrous oxide and some other gases, including some rare and particularly vicious ones, like the industrially produced SF5 CF3.2
In 2001, more than a thousand of the world’s top scientists (including prominent dissenters), grouped since 1988 under the Intergovernmental Panel on Climate Change (IPCC) issued a voluminous three-part report that was much more alarming than two previous reports released in 1990 and 1995.
FIGURE 12.1 Variations of the Earth’s Surface Temperature. © 2001 IPCC. Used by permission.
Starting with what’s already happening, the 2001 report3 concludes that:
The earth has warmed by about 0.6°C since 1860, with the last two decades the hottest on record.
The increase in surface temperatures over the twentieth century exceeds that for any century, going back 1,000 years.
Rain precipitation patterns have clearly changed, with an increase in heavy precipitations in quite a few regions of the globe.
Ocean levels have risen 10–20 centimeters since 1900, most glaciers are retreating,4 and the extent and thickness of Arctic ice is decreasing in summer.
Bird migration patterns and the length of growing seasons have started to change.
Human activities have definitely been increasing the concentrations of greenhouse gases, and most of the warming in the last fifty years is human-induced. The emission of greenhouse gases is very uneven: the United States, for instance, emits 25 percent of carbon dioxide but has only 5 percent of the world’s population.
The IPCC’s look into the future makes for downright scary reading. It projects that carbon dioxide, surface temperatures, rain, and ocean levels will all increase globally because of human activities:
All the models used by the scientists project significant increases in carbon dioxide concentrations over the twenty-first century in the absence of vigorous policy changes.
Those models predict that the earth will warm 1.4 to 5.8°C (2.5 to 10.8°F) during this century, a much higher range than that projected five years back. Land-surface temperatures will rise more than the average.5
By 2100, the rise in ocean levels will range anywhere between last century’s already significant increase and a whopping 80–90 centimeters—more as a result of the thermal expansion of the ocean body itself than as a result of ice melting.
Extreme weather events will increase: heat waves, heavy downpours, floods, droughts, fires, soil moisture deficits, higher cyclone intensity, even weather-related pest outbreaks. There is a special anxiety about the possible effects of global warming on the ocean’s poorly understood currents.6 One worry among others is that the current-related “El Niño” conditions that did so much damage in recent years—from Central American floods to drought-induced forest fires in Indonesia—may start to persist.
The length of the growing season and bird migration patterns will change even more, and plants, insects, and animals will increasingly migrate towards the poles, and upwards to higher elevations.
These changes will have major effects, lasting for generations. Billions of people will be affected directly. Some societies may be able to adapt. But poor people will be least able to do so, particularly those living in developing countries. The list of consequences includes:
A decrease in water availability in many water-scarce regions, particularly in the subtropics.
A decrease in agricultural productivity worldwide, especially in the tropical and subtropical regions, with the meager consolation that for small temperature increases, agricultural productivity could improve at mid- and high latitudes, mostly in richer countries.
An increase in mortality due to heat stress, insect-borne diseases (malaria), and water-borne diseases (cholera).
A widespread increase in the risk of flooding for tens of millions of people due to heavy rain and rising sea levels. Nearly onethird of the world’s population lives within 100 kilometers of a shoreline. Places like Tuvalu, where 10,000 people live on atolls, could be wiped out, 7 as could more than 15 percent of Bangladesh’s land surface. If oceans rise only 50 centimeters this century, more than 90 million people will be displaced.
Irreversible damage to glaciers, coral reefs, atolls, mangrove systems, and polar and alpine systems—on which the livelihoods of millions depend.
Reading this list of consequences, I find it hard not to feel depressed. First, because of the sheer scope of the changes afoot and their apparent irreversibility. Even if we succeeded in stabilizing carbon dioxide concentration in this century, the IPCC scientists predict, ocean levels would still continue to rise for hundreds of years. Second, one readily suspects that the “dog years” concept (Chapter 6) applies here more than anywhere else—one year lost in addressing the problem is like seven years lost, in a manner of speaking.
Yet, there is good news. There are many technological and policy options for addressing the global warming challenge, along three lines.
First, stabilization of the concentration of greenhouse gases is a must, and it is a realistic option. For example, there are known technological solutions for stabilizing carbon dioxide concentration at 450–550 parts per million (about twice the preindustrial level) in this century. This will require emissions reductions in all regions, including ten to fifteen years from now in developing countries, which by then will have exceeded the carbon emissions of rich countries. Emission ceilings for countries, regions, sectors, and firms would be one way to achieve this. An intriguing solution: assign an overall greenhouse gas concentration target and allow all countries to claim their right to share the resulting “emissions pie,” with their per capita entitlements starting wide apart and then converging to equality over a predetermined period.8
Second, and related to this, the world will need to move towards an increasingly different energy profile. We can achieve this through higher energy efficiency (dramatically cutting the use of energy per unit of GDP); through a determined “decarbonization” of the world’s energy system, meaning a massive switchover to hydropower, solar energy, and wind turbines, as well as more gas development (gas emits less carbon dioxide than oil and coal); and through innovative solutions such as underground carbon dioxide storage.
Some new technologies are especially promising. Very thin wallpaper-like solar panels could turn almost any large object into a power station, and fuel cells could act as storage devices to offset the variability of solar power. There’s a huge potential for increased energy efficiency: at equal wealth, some European countries have a per capita energy consumption 50–75 percent lower than that of the United States; and many developing countries could substantially increase the energy efficiency of their industries.9 There are some intriguing ideas around for carbon dioxide storage: for example, after stripping it from gas streams through membranes or other methods, injecting it into depleting oil fields, with a bonus of enhanced oil recovery.10
Taxes and tax incentives could also play a key role in getting the world to switch to a more sustainable energy profile (see Chapter 14). So will the eventual elimination of worldwide subsidies on fossil fuels, which surpass even the rich countries’ astronomical agricultural subsidies and which almost always benefit mostly the well-off.
Third, forests, agricultural lands, and other ecosystems offer enormous opportunities for “sequestering” carbon dioxide, perhaps up to 200 gigatons of carbon over the next half century.
Clearly, massive changes are required, on several fronts at once—and well beyond what the Kyoto Protocol, diluted and without the United States, will achieve. Most people have a keen sense of this. What is less well known is that these changes are affordable if the problem is tackled early. The IPCC estimates that changes aimed at stabilizing carbon dioxide concentration would entail a loss of GDP between 0.2 and 2 percent—which could be brought down by half to a loss of between 0.1 and 1 percent or less through various means.11
The modesty of this bill is typical of all twenty inherently global issues. It is modest both in absolute terms and by comparison with the potentially enormous long-term planetary costs of leaving the issue unattended. And yet, global warming and the Kyoto Protocol provided us in Chapter 10 with the first, most glaring example of the failure by the current international setup to solve urgent global issues.”