According to the Intergovernmental Panel on Climate Change (IPPC), increases in average global air and ocean temperatures, a widespread melting of snow and ice, and rising sea levels, all signal that our climate is changing. Indeed, the IPCC AR4 Report of November 2007 makes absolutely explicit their view that "warming of the climate system is unequivocal".

Climate change is occuring because the level of carbon dioxide and other greenhouse gasses in the atmosphere is increasing. The level was at about 280 parts per million (ppm) before the Industrial Revolution, and had risen to 317ppm by 1958 when detailed measurements began to be taken. Today, greenhouse gas levels are around 430ppm and are expected to increase to somewhere between 450ppm and 550ppm depending on the level of action to constrain their emission we globally choose to take.

Raised greenhouse gas concentrations in the atmosphere cause climate change because they lead to an increased retention of heat from the Sun. As a consequence, the IPCC predicts that average global temperatures will rise by a minimum of 1.1 degrees centigrade and a maximum of 6.4 degrees centigrade by 2100.

Climate Change Implications

A global temperature rise of a few degrees may not sound like much. However, even this degree of warming will have major implications. For example, a two degree rise in average temperatures is anticipated to lead to a 20 per cent fall in crop yields across Southern Europe. Estimates suggest that between fifteen to forty per cent of all species also face extinction in the face of a two degrees centigrade increase in average global temperatures.

Due to increased glacial melting, climate change will also cause sea levels to rise. Over the past century global sea levels have already risen by 17cm, and the IPCC expect the oceans to rise by a minimum of 18cm and a maximum of 59cm by 2100. In turn this means that between 75 and 200 million people face flooding risks due to climate change. If temperatures rise by three or four degrees, then sea level rises will threaten to inundate many major metropoli including London, New York, Tokyo and Hong Kong.

More broadly, most people will be impacted by climate change to a greater or lesser extent as we experience more extreme weather and related disruption. In particular, climate change is likely to lead to rising food prices as more crops are destroyed by increasingly "freak" weather.

Greenhouse Gas Emissions

Most greenhouse gas emissions result from burning fossil fuels, making cement, clearing land, and agricultural production. Most people understand that burning coil, oil, natural gas or wood releases carbon dioxide into the atmosphere, and if we want to reduce greenhouse gas emissions that we need to consume less of these fuels. However, what is less well advertised is the impact of deforrestation on greenhouse gas emissions.

When trees are felled, and when land is burnt to be cleared for agricultural purposes, the carbon dioxide held by the vegetation and peatland is released into the atmosphere. Indeed, according to the Global Canopy Programme, deforestation is currently responsible for around twenty-five per cent of all carbon dioxide emissions. One way to control climate change would therefore be to put in place incentives for people to cut down fewer trees and destroy less rain forest every year.

Climate Change Solutions

Some level of continuing climate change is now inevitable. As China, India and other rising economics rapidly industrialize, a level of climate change with very siginifcant implications is also quite likely unless pretty drastic global action is taken. For example, the Stern Review conducted for the United Kingdom Government in 2006 suggested that power generation will have to be decarbonized by between sixty and seventy-five per cent by 2050 to stabilize greenhouse gas levels at or below 550ppm and so prevent very serious levels of global warming.

The most obvious way to prevent too great a level of future climate change is to burn fewer fossil fuels, or at least to capture and store the carbon dioxide released when such fuels are burnt. This could involve the exploitation of alternative energy sources (including lunar helium-3, not to mention solar energy and wind and wave power). However, rather than focusing on finding new ways to power our machines, another alternative would be for most people to adopt more local living and to consume less energy in the first place. As already noted, greenhouse gas levels could also be lessened by reducing deforrestation. They would also be reduced if we built with less cement and ate less meat (as all livestock emit the greenhouse gas methane from their digestive systems).

As it begins to bite, climate change may also be tackled via future large-scale, macroengineering projects. For example, nanotechnology may one day permit the construction of a suite of atmosphere filtration plants around the globe could enable greenhouse gasses to be removed from the atmosphere and their levels stablized. Indeed, to cite nanotech guru Eric Drexler, "molecular manufacturing capabilities based on advanced nanotechnology will make it possible to reduce CO2 concentrations to pre-industrial levels within a short time span". As another alternative, synthetic biology may allow the creation of new forms of ocean algae that will absorb more carbon dioxide and so lower atmospheric concentrations.

A white paper presented by Kenneth I. Roy in 2001 suggested that 100,000 square kilometres of solar sails may be sufficient to allow us to take control of climate change. Unfortunately, building such sails on the ground and then launching them into space is unlikely to be possible. Solar sails would therefore probably have to be constructed in space, maybe using raw materials mined from the Moon or asteroids. Alternatively, materials may be lifted into orbit using a future space elevator that would climb into orbit up a very long, carbon nanofibre cable.

The construction of solar sails to control global warming may at first sound like an impossible endeavour. But so too did sending a human being to the Moon in the 1960s, and that mission had no planet saving ambition. As the decades turn, space-based solar sails could also turn out to be a more viable solution to global warming than persuading billions of people to radically change their lifestyles. If you like, why not watch my Global Warming Solar Sails video?

A Political and Business Certainty

Climate change remains a controversial topic. Some people still do not believe in it, many people believe it is a natural process and not the result of human action, and yet others think that any actions to prevent climate change are either futile are too costly in comparison to the implications. This said, the link between climate change and the emission of greenhouse gasses resulting from human activity is now largely accepted by most citizens and governments. As a result, whether or not and to what extent this link really exists is becoming pragmatically irrelevant. This is because most of us now find ourselves living in and/or trading with countries in which both government action and consumer behaviour are at least partially directed toward a reduction in greenhouse gasses. Businesses therefore now need to strategically plan within an environment that is changing not just physically, but also in terms of market regulation and consumer expectation. For this reason alone, pretty much everybody on the planet will be increasingly impacted by climate change in the very immediate future.

More information on climate change can be found in my book 25 Things You Need to Know About the Future. A list of climate change web references can be found here.