Our common future is at risk from climate change. Behind the summary numbers - £74 trillion of cumulative global damages, the social cost of carbon at £70 per tone and rising - lies a story of multiple, interacting, and worsening harms. The first 2º of climate change will be costly in terms of economic disruption; lives lost or shortened ecosystems damages, and species extinctions. Even with gradual average changes, the variability of temperatures and rainfall, as well as extreme storms, will have enormous costs. Before 2050, this will very likely be bad for developed countries, which have already begun to experience more severe hurricanes and heat waves. It will be much worse for developing countries, which will suffer greater losses and will have more limited resources to respond and adapt. (Source H)
Source I
The 21st century is not yet a dozen years old, and there are already 1 billion more people than in October 1999 - with the outlook for future energy and food supplies looking bleaker than it has for decades. It took humanity until the early 19th century to gain its first billion people; then another 1.5 billion followed over the next century and a half. In just the last 60 years the world's population has gained yet another 4.5 billion.
Simultaneously, we need a swift transformation of energy, water, and materials consumption through conservation, efficiency, and green technologies. We shouldn't think of these as a sequence of efforts - dealing with consumption first, because population dynamics take time to turn around - but as simultaneous work on multiple fronts.
Source J
Energy has never been used so lavishly as it is today; one calculation suggests that more has been used by humanity during the last century than during the whole of previous history - say, in the last 10,000 years. Eighty-seven per cent of this energy comes from fossil fuels, created from the fossilized remains of plants accumulated in the earth's crust over millions of years. Reserves are running out just as thousands of millions of people hope to raise their levels of consumption to current levels in the West. This is clearly an unsustainable situation. Many governments and companies are now investing much in developing 'sustainable' forms of energy, such as geo-thermal, solar, tide, wind and waste. But in reality very little progress has been made over the past decades, especially in developing applied technologies based on these resources. With nuclear energy still encountering much resistance, humankind is facing a bleak future in energy terms.
Source K
Where the rest of the world has seen an explosion in agricultural productivity that has mainly outstripped population growth, Africa produces less food per capita now than it did in 1960. The average calorie consumption is about 600 calories less than required. In some parts of Africa, as much as a third of the population are reliant on some degree of food aid. About 40 years of structural transformation has yielded almost no growth.
Using the Study Sources H, I, J, and K. and your own knowledge, explain why climate change, population growth, and energy consumption constitute a global threat.