Enthusiast's Guide to Climate Change

Hungry for more information on climate change? Our Enthusiast's Guide tackles some of the more complicated issues around the topic.

If you're looking for an overview of climate change, try our Easy Guide to climate change.

When will we feel the effects of climate change?

We're already feeling the effects of climate change. We know that seven of the past 10 years have been the warmest since records began in 1880, and 2007 is expected to be the hottest year ever.

Around the world, especially at the North and South Poles, the reality of rising temperatures is even more stark. Recently, the Arctic Inuit population issued a warning to the world: their villages are already so damaged by global warming that relocation is their only option.

As we learnt in the Easy Guide, there is now near-total agreement among the experts that our climate is changing, and that extreme weather events are occurring more frequently.

The emissions time-lag

The climate change effects we're experiencing today are the result of carbon dioxide (CO2) we have emitted over the last century. About half of human CO2 emissions are absorbed by vegetation and the oceans (Le Quere et al (2007), Science Online) - but the remaining CO2 can persist in the atmosphere for a hundred years or more.

As a result, even if we were to halt all carbon emissions today, the climate would still be affected by the backlog of CO2 already in our atmosphere. This doesn't, however, mean that we can't have a positive impact on our climate - see Reversing environmental damage below.

What could happen over the next 50 years?

Predicting future warming is more challenging than it sounds. The Earth's climate is a complex system - more complex than the most advanced computers making accurate predictions difficult.

If we don't start to curb carbon emissions now, everyone can expect to feel these effects some sooner than others.

The worst-case scenario statistics make for gloomy reading. If we take no action, the amount of CO2 in the atmosphere could double within the next 50 years. The charity Christian Aid estimates that, on current trends, up to 1 billion people will be displaced from their homes by 2050 and that climate change will become one of the major reasons for displacement.

The Intergovernmental Panel on Climate Change predicts that by 2080:

• ­1.1 to 3.2 billion people will be experiencing water scarcity
• 200 to 600 million people will be suffering from hunger
• 2 to 7 million people per year will experience coastal flooding

Although many news reports talk about the effects of climate change in far-away places, the reality is that it will affect us all. For example, the UK Climate Impacts Programme (a government agency) predicts that the UK will experience warmer, drier summers making summer droughts more likely and wetter winters with less snow.

Reversing environmental damage

It's not all doom and gloom. If we act now, we can help to reduce the scale of these climate impacts.

There is a precedent for this kind of action: the global response to the hole in the ozone layer, which posed a huge threat to the world's health in the 1980s. The ozone hole was caused by chlorofluorocarbons (CFCs) and other gases often used in aerosols, fire extinguishers and refrigeration.

The solution required cooperation from every nation in the world. An agreement was secured requiring industry to cease production of the ozone-destroying gases and develop more 'ozone-friendly' substitutes. As a result, ozone depletion has dramatically slowed and the ozone layer is expected to recover fully within the next 50 years.

This example of a global solution to an environmental problem provides a valuable lesson for tackling climate change. As Al Gore says, We assume that the earth is so big we can't have any impact on it. This is no longer true.

Turning back the clock on climate change

Because of the persistence of CO2 in the atmosphere, it's unlikely that we'll be able to reverse the changes we have already made to the climate. However, we can limit future non-essential emissions.

A study by NASA shows that a business-as-usual scenario (where no action is taken to halt CO2 emissions) is likely to result in a temperature rise of 3-5 °C (about 5-9 °F) by 2100. According to the WWF, we have the know-how to limit the expected temperature rise across the planet to 2 °C (4 °F). That may not sound like a big difference, but even one degree above the 2 °C 'threshold' is enough to put more than 100 million more people at risk of malaria, up to 500 million more people at risk of water shortages, and more than double the number of people at risk from coastal flooding globally.

Reducing emissions

Humanity already possesses the fundamental scientific, technical, and industrial know-how to solve the carbon and climate problems of the next half-century. (Robert Socolow and Stephen Pacala, University)Princeton

Socolow and Pacala's 'stabilisation wedges' show how the world can, using existing and affordable technologies, reduce current levels of carbon emissions back to the levels emitted in the 1970s through a series of goals.

This is an exciting and feasible prospect for the whole world but one that requires international cooperation. The plan of action is clear. The large-scale solutions in this model lie in a mixture of:

• creating more energy efficient heating and cooling systems, lighting and electronic equipment
• designing buildings and business practices to use less energy
• manufacturing cars that use less petrol or non-polluting fuels such as hybrids
• providing better public transport systems in towns and cities and design more fuel- efficient, long-distance vehicles
• generating a high proportion of energy from renewable energy sources such as solar and wind power
• capturing and storing any excess carbon from power stations in the deep ocean-bed or in deep underground rocks

However, most scientists agree that climate change is unlikely to be slowed by technological fixes alone. In order to halt the rate of growth of CO2 emissions, we will all need to change our lifestyles. Some actions we can take include:

• promoting energy efficiency in industry and the domestic sector
• reducing high emissions travel, such as flying, and promoting the use of public transport
• consuming less, reusing what we can, and recycling the rest
• buying food from local, organic sources

Emerging into a cleaner world

In industrialised countries, we're all aware of the steps we can take to help reduce CO2 emissions. But the real growth in carbon dioxide looks set to come from developing countries such as China and India.

China, for example, is second only to the US as an emitter of carbon dioxide. Although the average US citizen uses nearly 10 times as much energy as an average Chinese citizen, the sheer size of population - and its high rate of economic growth means that it is expected to become the world's biggest emitter of CO2 by 2010 at the latest.  In fact, the Netherlands Environmental Assessment Agency claims that it already has.

Since developing countries are not required to reduce their carbon dioxide emissions under the Kyoto Protocol, China's emissions increase over the next few years may cancel out the cuts made in industrialised countries.

However, there are signs that China's leaders are taking climate change seriously. In 2004, plans were announced to generate 10% of China's power from renewable sources by 2010.

China has set a target of reducing the country's energy consumption per unit of GDP by 20% over the next five years. Their plans include the creation of an eco-city, Dongtan on Chongming, China's third-largest island. The resident population of 50,000 will drive hybrid cars or pedal bikes; homes and businesses will be powered by green energy; and more than half of the island has been set aside for food production to minimise unnecessary food miles.

It is difficult to predict the future of global CO2 emissions, especially when the climate policies of the biggest emitters are unclear. Alongside its aims to reduce energy use by a fifth, China has recently voiced its intention to make economic development its priority, above environmental concerns. Despite the uncertainty elsewhere, what we can be sure about is that, by reducing our own carbon emissions, we can play our part in combating climate change.

People power

Some of the activities mentioned in this guide may seem like large-scale actions, beyond the power of individuals. But by voicing your concerns about climate change, you can join a growing number of people encouraging governments and businesses to address the issue and cut carbon emissions.

Governments and businesses will do what the public (their voters and customers respectively) demand of them. As anthropologist Margaret Mead once said: "Never doubt that a small group of thoughtful people can change the world; indeed, it is the only thing that ever has".