287) Mitos do aquecimento global

Carbon myths
Recycling and banning plastic bags are all very well, but they won't save the planet. Instead, we should fly less, go vegan and insulate the loft, says Chris Goodall
Chris Goodall
The Guardian, Thursday December 13 2007

The global warming consequences of our personal actions are usually invisible to us. We have no easy means of knowing how our way of life generates carbon dioxide and other climate-changing gases. It is far from obvious that it takes more energy to produce a paper bag than its plastic equivalent, or that extra loft insulation usually reduces gas consumption more than solar panels. Unsurprisingly, this means that most of us are ignorant about what really matters, which makes us vulnerable to comforting half-truths. These myths are a problem in themselves because they discourage us from addressing the important sources of emissions. But our ignorance also encourages businesses to promote goods and services that offer little or no carbon-saving.

So, for example, when British people are asked in surveys about the actions they can take to be more responsible about global warming, domestic recycling always comes top. Reducing air travel comes far down the list. But the global warming impact of our Mediterranean holidays is hundreds of times more than the toll from not recycling. We see the plastics going into the dustbin every week, but pollutants from jet engines are hidden. So people who carefully sort their recycling every week continue to fly. And businesses that are trying to be ethical devote more effort to reducing packaging than getting their employees to travel less.

We like our myths. Suggesting that British league football isn't the best in the world or that Monty Python wasn't always funny is a quick way to start an argument and lose friends. But some of our cherished carbon myths are dangerously counterproductive. Here is my list of the most common:

I like low-energy lightbulbs. In fact, I sell them at the local farmers' market to offset my personal carbon sins. But even if a householder replaces all their bulbs, the total impact on yearly electricity consumption is likely to be no more than about 400 units (kWh) of electricity. A new plasma TV bought at the same time will outweigh any energy savings. The government talks about banning old-style bulbs, but no one dares mention the explosive impact on energy consumption of the latest generation of large TVs and games consoles. The power used by these monsters embarrasses their manufacturers and the online brochures usually omit all details of electricity use. I couldn't find a single retailer that dares to list the power consumption of plasma TVs. The best rule for cutting home electricity consumption? Keep your old TV. If you still feel the need to buy something, get a new super-efficient fridge.

Nothing arouses fury like the disposable plastic supermarket bag. Gordon Brown singled them out in his first speech on climate change as prime minister. The widespread hatred now extends to almost all plastic food packaging. But although plastic bags are detestable, they are almost irrelevant to climate change.Each of us uses about 2kg a year of shopping bags, and they perform multiple useful functions in the home after they have carried our shopping from the supermarket. Food packaging of all types is no more than 5% of the weight of our groceries. Wasted food, which rots in landfill and generates methane, is a far more serious cause of global warming. Rather than getting our retailers to strip the 3g of protective polythene from our cucumbers, we need to concentrate on reducing the 30% of food that goes to waste every week.

There is nothing wrong with hybrid petrol/electric cars. But they are an extraordinarily expensive way of avoiding emissions. The Toyota Prius may be lovely, but its emissions are no better than the latest generation of small diesels, which cost little more than half the price. Buy a small car instead and spend the savings on insulating your walls. It will have far more effect. Worried about the effect on your status of driving a small car? Buy an electric vehicle and people will simply think of you as eccentric.

It makes sense to avoid unnecessary transport of food. Local food is fresher and probably healthier, and your purchase contributes to the local economy. But food transport, unless it is by air, is usually a relatively small part of a meal's carbon impact. Reducing the amount of meat you eat has far more effect than deciding to buy locally. A kilo of beef from the farm next door will have 50 times the global warming effect of a can of beans shipped from Canada.Taking a few steps towards a vegan diet will reduce carbon emissions far more than local purchasing. Avoiding meat and also buying locally is better still.

Politicians extol the virtues of domestic generation of electricity. The Conservatives and Liberal Democrats have committed themselves to paying us 45p a unit for electricity from the solar panels on our roof, about 10 times the wholesale price paid to the large, coal-fired Drax power station, in North Yorkshire. Microgeneration may be fashionable, but it is an astonishingly expensive way of reducing emissions. Less glamorous, but more effective, would be a plan to put a £20 note in the centre of every roll of loft insulation. British houses are the worst insulated in northern Europe and subsidised insulation would cut emissions far more cheaply than encouraging wind turbines or solar photovoltaic panels

Myth 1 Eco lightbulbs are the best way to save electricity at home
Myth 2 Flying is responsible for only 2% of carbon dioxide emissions
Myth 3 All packaging is wicked
Myth 4 Hybrid cars are the way forward
Myth 5 Avoid food miles
Myth 6 Microgeneration is a good way for Britain to cut emissions

· Chris Goodall is the author of How to Live a Low Carbon Life (Earthscan) and founder of carboncommentary.com