Climate change is arguably the single most important long-term sustainability issue facing the planet. But we have the knowledge and the resources to reduce its extent and deal with its impacts—and the sooner we act, the better it will be for current and future generations.

During the last century, the average global temperature has risen by almost two degrees Fahrenheit. The broad consensus of both scientific and political communities on this matter is reflected in the key findings of the recent Intergovernmental Panel on Climate Change (IPCC) synthesis report.

• Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.
• Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in greenhouse gas concentrations resulting from human activity.
• There is high-level agreement and much evidence that current policies and practices will mean an increase in greenhouse gas emissions over the next few decades, causing further warming that will very likely be larger than that observed in the 20th century.
• Projected sea level rise by 2100 is estimated at 10 to 30 inches. However, climate change could lead to some impacts that are abrupt or irreversible, and more rapid sea-level rise of the order of feet, rather than inches, can’t be excluded.

This consensus is leading many national governments to implement new regulations, legislation, carbon trading schemes and fiscal measures to curb emissions of greenhouse gases, the most important of which is carbon dioxide.

In addition, several nations are now planning to accommodate the likely impacts of climate change, for example, by raising flood defense standards. These actions aim to counteract the future impacts of climate change by designing projects to be adaptable to likely changes. Where currently implemented, such measures are usually being applied to major infrastructure and development projects, as it is accepted that the costs of making these projects adaptable to climate change are reduced if included as part of the original design, rather than as a later retrofit.

If greenhouse gases continue to rise at their current rates, scientists predict a much warmer world by the end of the 21st century, with potentially catastrophic impacts in terms of flooding in some parts of the globe, reduced availability of water in others and generally more extreme weather events. Indeed, these impacts have led many authorities to see climate change as a national security issue.

Energy Supply
Linked to climate change is the issue of ensuring a secure energy supply in future years. By 2040, the world’s population—currently 6.7 billion—is likely to increase by more than two billion. When the increased energy consumption associated with rapid industrialization in China and India is factored in, it becomes clear that there is likely to be a continuing growth in oil demand over the next couple of decades—even if everything is done to improve energy efficiency and optimize the use of low-carbon energy sources.

The dangerous combination of rising energy demand and limited supply of easily recoverable oil reserves, combined with policies to tackle greenhouse gas emissions, has led many energy forecasters to identify a future predicated on new factors: increased use of renewable energy sources; continued coal use, but with the focus on clean coal and carbon capture and sequestration; and a continuing rise in oil prices associated with a tight match between demand and supply. Nuclear energy is also back on the agenda in many countries.

The issues surrounding some alternative energy sources are extremely complex. For example, biofuels are now being developed as a source of energy for transportation. But there is uncertainty over the degree to which the current generation of biofuels will reduce carbon emissions, and it is also recognized that the use of agricultural resources for biofuels production can have an alarming effect on food prices.

Tackling the Issues
Climate change will have a significant effect on the way the world operates because it will affect basic human requirements such as food, water, energy and transportation. It is not something we can ignore. We can only reduce its future impact if we act decisively to limit the factors that cause it. Even then, it will take years to see the benefits of our actions. But the sooner we recognize that we have the ability, the technology and the will to lessen its impacts, the sooner we can implement changes that will actively reduce the emissions that threaten current and future generations on this planet. iBi