How you can help
There are two things we need to do:
The first is to reduce the greenhouse gas emissions responsible for climate change. By choosing cleaner ways to power our homes, offices, and cars, and being more efficient and less wasteful, we can produce fewer greenhouse gas emissions.
Everyone can play a part in a clean energy future, including government, businesses, and you. There are lot of things you can do to help, like turning off the lights when you leave a room to reduce the electricity you use, taking shorter showers to reduce the water you use (and the energy it takes to process, move, and heat it), planting a tree to absorb carbon dioxide, or recycling to reduce waste. For example, recycling aluminum is 90-95 percent more energy efficient than producing aluminum from raw materials.
Look for more ideas on what we can do together and individually.
The second is to prepare for life in a changing climate. We need to make sure our buildings, roads, businesses and all the services they use can withstand the climate changes that we can’t avoid.
Learn how communities and companies are preparing.
C2ES thanks the Alcoa Foundation for its support, which allowed us to develop our Climate Classroom content. As a fully independent organization, C2ES is solely responsible for its positions, programs, and publications.
What can we do? Global warming is such a mammoth problem it is hard to know where to start. Will turning down the heating, recycling rubbish and planting a tree be enough? Or are governments going to have to force us to count up our carbon emissions and change our energy-guzzling ways?
What role can governments play; can scientists and engineers offer any solutions, and are there any ways we at home can make a real difference? We talked to some of the world's leading experts to find out about the best ways of tackling arguably the greatest threat mankind has ever faced.
What governments can do
Greenhouse gases don't respect national boundaries, making global warming an international problem that no one country can tackle alone.
"At the highest level, the key role of governments is to set up internationally agreed global frameworks to tackle climate change," says Mike Hulme, director of the Tyndall Centre for climate change research at the University of East Anglia.
The Kyoto protocol was supposed to be just that, but many people feel that without the US - the world's biggest CO2 emitter - the treaty will have little impact. Hulme disagrees: "Kyoto is absolutely critical, not for what it will deliver by 2012, but to show that there can be collective action."
However, there is no 'one size fits all' solution and instead, solutions need to be tailored to fit the needs of individual countries.
"Governments of developing countries face different challenges, but there are substantial benefits for going down the low carbon route, such as security of energy supply and better air quality," says Hulme. In rapidly developing countries, such as China and India, greenhouse emissions are increasing at an alarmingly rate and Western governments have a responsibility to help.
"We have an opportunity to influence the practice that they adopt and it is our duty to share the clean technologies that we develop," says Andrew Ives, president of the Institution of Mechanical Engineers.
At the national level, governments need to persuade people to change their ways. "With individual citizens, the carrot-and-stick approach can be used with things like penalties for buying large and inefficient cars," explains Hulme. For businesses, however, a different approach is needed. "Governments need to set out long-term targets and frameworks for businesses, so that they can plan for the future and know that their investments in things like low carbon technology will be worthwhile," says Hulme.
But no matter how hard governments try, they won't be able to stabilise the effects of global warming immediately. "Climate change will not be solved in our lifetime, or that of the next few generations," says Hulme. "Instead, governments must ensure that we can cope with future weather conditions in 20, 50, even 80 years down the line.
"For example, buildings in the future may need to be able to cope with driving rains in winter and temperatures of more than 35C in summer - something that needs to be considered in building regulations today."
These decisions are very difficult for governments to make, and could not be done without the help of climate scientists and engineers. "Governments can play a major role by funding research to establish the basic science behind climate change," says Hulme.
All over the world, scientists are working hard at understanding our climate and coming up with ingenious solutions for tackling the global warming problem. So what are they suggesting?
What scientists and engineers advise
First up is cleaner, greener forms of energy. Driving a car accounts for about 40% of the average person's greenhouse gas emissions, so developing low emission cars could make a real difference. Bio-power cars, such as those produced for Saab's 9-5 range, run almost entirely on wood chip, wheat and sugar.
Meanwhile, hybrid cars, such as the Toyota Prius, combine the power of a petrol engine with the efficiency of an electric motor. Biopower cars are already popular in Brazil and Sweden, while congestion charge exemption and tight emissions laws have made hybrids the latest fashion accessory in London and California, respectively. "By building on today's technology, we avoid the problem of introducing a completely new infrastructure," says Andrew Ives.
Hybrids and biopower cars can certainly help to cut CO2, but is it possible to go one step better and produce no greenhouse gas emissions at all? David Hart, head of fuel cell and hydrogen research at Imperial College London, certainly thinks so. "Fuel cell vehicles using hydrogen created from renewable power emit virtually no carbon, so switching over to fuel cells could have very great benefits in the long term," he says.
Fuel cells work by converting chemical energy into electrical energy, like a battery, but with a continuous supply of fuel. "The great advantage of a hydrogen fuel cell is that its only product is water," says Hart. Ideally, the fuel would be produced by electrochemically splitting water into hydrogen and oxygen, using renewable energy such as wind power.
Extrapolating from current vehicle emissions, Hart has calculated that CO2 emissions from vehicles could drop to nearly zero by 2050 if everyone started to adopt hydrogen fuel cell cars. But the problem is encouraging people to switch over. "Hydrogen is not used outside demonstrations and its introduction would be a major shift," says Hart.
In the short term, we are more likely to see fuel cells doing the job that conventional batteries do. "Within the next few years, you may be charging your mobile phone with a methanol fuel cell," says Hart. And in the medium term, biomass, or natural gas fuel cells, might replace conventional boilers to provide super-efficient heating.
More than a third of the average UK person's greenhouse emissions come from energy used at home, so finding new ways of heating and powering homes is a priority.
Robert Mather, of Heriot-Watt University in Edinburgh, is developing solar-powered clothing and fabrics. The challenge is to create solar cells that can bend as the fabric moves, creating flexible solar panels and possibly even solar clothes. "We envisage these new solar cells on curved surfaces of buildings, or as transportable power that can be rolled up and moved around," he says.
Nonetheless, there is a limit to what solar power can do in the UK, so what about the other renewables: wind, wave and tide?
"If wind, tidal and wave power were developed to their full potential, they could provide 40% of the UK's power needs," says Graham Sinden, from the Environmental Change Institute at Oxford University. Add hydrogen fuel cells and you overcome the intermittent supply problem of renewables; combine with hi-tech biomass and landfill gas boilers, and you are more than halfway there. However, unless we all wear more woolly jumpers in winter, we still have to find more energy from somewhere else.
Kenneth Fergusson, president of the Combustion Engineering Association, believes the answer lies in clean coal technology.
"By gasifying coal before we burn it, we can remove the CO2 and turn coal into a carbon neutral fuel," he says. This technique is already being used in power stations in the US and China.
But what happens to the CO2 from the gasification process? Howard Herzog, from Massachusetts Institute of Technology, is looking into ways of storing it underground. Capturing CO2 from power plants and pumping it into the ground is feasible; the difficulty is in finding storage where there is no chance of it escaping for thousands of years. "Empty oil and gas fields are good places, as we know they have already managed to seal fluids into the ground for millions of years, but their capacity is somewhat limited," says Herzog.
Another possibility is a very common rock formation known as a saline aquifer. "These contain a dome-like structure, which can be filled with CO2, just like an upturned cup," says Clair Gough, a Tyndall Centre researcher based at the University of Manchester.
Experimental carbon storage projects already exist, including one under the North Sea, which swallows 1m tonnes of CO2 every year from a gas field just off Norway. "There is still more work to be done in surveying the geology of saline aquifers, but in theory we could store decades-worth of CO2 from UK power stations in rocks below the sea bed around the UK," says Gough.
Perhaps more extreme is the idea of getting the ocean to gobble up CO2. "Experiments have shown that adding iron to certain parts of the ocean can encourage the growth of algae, which draw down CO2 from the atmosphere," says Dorothee Bakker, from the University of East Anglia.
Unfortunately, the most suitable ocean is the environmentally sensitive Southern Ocean, around Antarctica. And no one is sure exactly how much of the carbon gets locked away at the bottom of the ocean, and how much might bubble back out again. "Calculations suggest that if we fertilised around 10% of the Southern Ocean we would draw down around 2% of the CO2 that we release into the atmosphere at the moment," says Bakker.
If reducing energy consumption and gathering up CO2 are not sufficient to solve the global warming problem, some scientists say we may need to turn down the Earth's thermostat.
John Latham, from the National Center for Atmospheric Research in Colorado, has come up with an idea to make the clouds more reflective, bouncing more sunlight back into space and helping the Earth to cool down. "Modifying clouds over around 3% of the Earth's surface would be enough to balance out the warming from doubled levels of atmospheric CO2," he says.
Meanwhile, Lowell Wood, from the University of California's Lawrence Livermore National Lab, has ideas for reflecting sunlight from higher up. "The quick and dirty solution would be to fire particles into the Earth's stratosphere, which would enhance scattering of sunlight in a similar way to violent volcanoes like Pinatubo," he says. "With just a modest amount of particles we could scatter around 1% of incoming sunlight."
More ambitious still is Wood's idea to scatter sunlight before it even reaches the Earth. He has suggested using rockets and solar sails to place a hi-tech transparent screen between the Earth and the sun, which would bend a fraction of the light and bounce it around the sides of the Earth. "The screen would be made from exceedingly fine wire, which would diffuse the infra-red portion of the sunlight and make it skitter around the Earth," says Wood.
Much as the idea of technological fixes like these are appealing, it is unlikely that we would all manage to agree on such drastic solutions. Smaller changes are easier for governments to implement, and therefore more likely to be introduced. Most of us have very little say in these big decisions, but we can still help to tackle the problem.
What we can do
"If everyone in the world moderated their transport use, made small changes to their home energy and paid attention to the foods they ate, then we would achieve the Kyoto protocol targets six times over," says Dave Reay, an environmental scientist at the University of Edinburgh and author of Climate Change Begins at Home. According to Reay, just small changes in lifestyle can make huge differences.
One of the most significant contributions we can make is to change the type of car we drive, or better still, take public transport. "A large four-wheel drive produces around three times as much CO2 as a 1.3 litre car," Reay says.
Flying is another problem. "It is not necessary to cut out flying completely, but to try and opt for the train over a short-haul flight, as these flights are the least efficient per kilometre."
And if you do fly, you can choose to offset your carbon and make your journey carbon neutral, by using an organisation such as Climate Care.
Very small changes in the home can also add up to big savings. "The biggest impact comes from things like better insulating your home, turning down the thermostat and wearing an extra jumper, and buying energy efficient appliances," says Reay.
Curbing your appetite for exotic foods and eating local produce can also help slash your emissions.
"By looking at individual actions and then multiplying them up, street by street, town by town and city by city, I found that small changes in lifestyle could make a huge difference," says Reay.
"For people in the developed world, these changes could amount to a 30% reduction in emissions if everyone did them."
There is no silver bullet solution to global warming, but it also isn't an impossible problem. While governments set up international policies, and scientists and engineers conceive technical fixes, we can all do our bit at home and be confident that it really is making a difference.
The next big thing: making cash from carbon
At the start of the year, a new market mechanism kicked in across Europe, with the sole aim of reducing member states' CO2 emissions to levels set by the Kyoto protocol. Although Britain set up an emissions trading system in 2002, many experts regard this European scheme as the most progressive in the world.
The principle behind emissions trading is simple. First, nations work out how much CO2 they are pumping into the atmosphere. Then they decide upon a tough but realistic reduction. Once a cap is set, any site or company that produces more than a certain amount of energy is allocated an emissions quota. If they want to emit more CO2, they must buy permits to make up the shortfall.
If a site or company introduces efficient new technology that cuts its emissions below the quota, it can sell permits up to that quantity to another company. By gradually reducing the cap, the scheme should reveal the cheapest ways to cut emissions across Europe.
Although widely praised, the system only covers 46% of Europe's emissions, significantly excluding those from transport and homes. In the US, nine north-eastern states are thrashing out a similar scheme. The hope is that the US scheme will eventually link with the European one, marking the start of a truly global emissions market.