IB Geography

oaking up CO2 directly from the air through the planting of trees.

Some people and organisations offset their entire carbon footprint while others aim to neutralise the impact of a specific activity, such as taking a flight

visits an offset website, uses the online tools to calculate the emissions of their trip, and then pays the offset company to reduce emissions elsewhere in the world by the same amount – thus making the flight "carbon neutral".

£8/$12 for each tonne of CO2 offset

carbon neutrality included as part of the price.

most of the best-known carbon offset schemes have long-since switched from tree planting to clean-energy projects – anything from distributing efficient cooking stoves through to capturing methane gas at landfill sites.

many people argue that offsetting is unhelpful – or even counterproductive – in the fight against climate change

Just as indulgences allowed the rich to feel better about sinful behaviour without actually changing their ways, carbon offsets allow us to "buy complacency, political apathy and self-satisfaction"

"Our guilty consciences appeased, we continue to fill up our SUVs and fly round the world without the least concern about our impact on the planet … it's like pushing the food around on your plate to create the impression that you have eaten it."

"a positive approach to offsetting could have public resonance well beyond the CO2 offset, and would help to build awareness of the need for other measures."

This boils down not just to the effectiveness of the project at soaking up CO2 or avoiding future emissions. Effectiveness is important but not enough. You also need to be sure that the carbon savings are additional to any savings which might have happened anyway.

The carbon savings would only be classified as additional if the project managers could demonstrate that, for the period in which the carbon savings of the new lightbulbs were being counted, the recipients wouldn't have acquired low-energy bulbs by some other means.

The problem is that it's almost impossible to prove additionality with absolute certainly, as no one can be sure what will happen in the future,

If that happened, the bulbs distributed by the offset company would cease to be additional, since the energy savings would have happened even if the offset project had never happened.

To try and answer these questions, the voluntary offset market has developed various standards, which are a bit like the certification systems used for fairly traded or organic food

Voluntary Gold Standard (VGS) and the Voluntary Carbon Standard (VCS).

One VGS-certified biomass power plant refused to allow her around, though staff there reported a number of concerns such as trees being chopped down and sold to the plant, which was designed to run on agricultural wastes.

f we're to tackle climate change, they argue, the projects being rolled out by offset companies should be happening anyway, funded by governments around the world, while companies and individuals reduce their carbon footprints directly.

Only in this way – by doing everything possible to make reductions everywhere, rather than polluting in one place and offsetting in another – does the world have a good chance of avoiding runaway climate change, such critics claim.

some carbon-neutrality advocates suggest offsetting carbon-intensive activities such as flights two or three or even ten times ove

The point is simply that the world is full of inexpensive ways to reduce emissions. In theory, if enough people started offsetting, or if governments started acting seriously to tackle global warming, then the price of offsets would gradually rise, as the low-hanging fruit of emissions savings – the easiest and cheapest "quick wins" – would get used up.

he base year, and 2010.

an average 8 per cent cut for most of Europe to a maximum 10 per cent increase for Iceland and an 8 per cent increase for Australia.

European Union have agreed to share out their entitlement

atification of the treaty in national legislatures.

“flexibility mechanisms”

meet some targets by encouraging the natural environment to soak up more CO2 rather than by cutting emissions.

carbon sinks”

qualify for carbon credits by planting forests that soaked up CO2.

It was finally agreed that countries will be able to claim some carbon credits for planting forests in developing countries. And they will also be able to allow countries to claim credit for activities such as soil conservation, which will allow more carbon to be soaked up in soils.

carbon trading

But the fear is that some countries may find themselves with spare credits to sell just because their economies have slowed down, which would undermine the whole purpose of the protocol.

hot air”. Japan, Canada and perhaps others would like to buy up Russia’s spare permits.

But sceptics still see hot-air trading as a Trojan Horse for undermining the protocol.

lean Development Mechanism. This allows industrialised countries to claim credit for various activities in developing countries. It could become a major engine for getting clean energy technologies into poorer countries, so heading them off the dirty path to industrialisation that the rich nations took.

And the rules are biased towards small energy projects – solar cell systems, for exampl

he protocol allows industrialised countries to plant “carbon sink” forests in the tropics, for instance, where they will grow faster. They can also invest in clean energy technologies in the developing world, and claim carbon credits for doing so.

The US has demanded, both before and after Kyoto, that developing countries should accept their own specific emissions targets

hard to police, particularly the clauses on carbon sinks.

at perhaps 1.5 per cen

Will the Kyoto measures solve the problem of global warming? They will hardly scratch the surface. T

say it will buy us 10 years at most

. A reasonable target might be twice pre-industrial levels, which works out at 50 per cent above today’s levels.

Cutting emissions by 60 per cent is a suggested figure.

The Kyoto Protocol was drawn up with the long term as the primary focus. In essence, the protocol assumes that what we really need to worry about is the climate in a century’s time, not today.

CO2 sticks around for about a century. Methane, the second most important greenhouse gas, generally lasts in the atmosphere for about a decade. But while it’s there it is many times more potent.

This “hundred-year rule” has the effect of downgrading the importance of methane, and giving only small credit to countries that try to cut methane emissions.

the protocol gives a country that reduces its methane emissions by a tonne 20 times as much credit as for reducing CO2 emissions by a tonne.

Cows can be given less gas-inducing feed. Leaks in gas pipelines can be plugged. And so on.

Technically, we are going to have to find many more ways of producing energy without burning fossil fuels – the so-called carbon-free economy. Politically, we are going to have to find a way of doing so which doesn’t affect the growing economies of the developing nations, whose responsibility for the build-up of greenhouse gases so far has been minimal. Some people think this will require moving towards equal pollution rights for every citizen on the planet, a policy endorsed by Britain’s Royal Commission on Environmental Pollution earlier this year.

pests that now thrive in the warmer air.

worm that became the scourge for him and neighboring farmers. It suddenly started devouring their crops in the early 2000s.

last year, came the rats.

the breaking point for his cotton crops came when red ants ate away the buds.

he has decided to plant sugar cane instead and move some of his production to higher altitudes where it is colder.

The idea’s supporters promised profits through exports to markets in North America, Asia and Europe, where the fruit seasons were reversed.

hey are shipped to China, where they are prized. Credit Tomas Munita for The New York Times

All told, more than 100,000 acres of desert were brought into cultivation.

With enough water and fertilizer, asparagus could be grown directly in the sand — and at yields per acre far higher than in the United States because Peru has no cold season and more days of sun.

A reservoir was created out of a dune. More than 8,000 tons of produce grows here every year.

The temperature at the site of the glaciers rose 0.5 to 0.8 degrees Celsius from the 1970s to the early 2000s, causing the glaciers of the Cordillera Blanca to double the pace of their retreat in that period

It was the start of a wave of migration from the mountainside to the coast set off by the arrival of the water.

14,000 feet above sea level.

“In years to come, we will be fighting over water,” said Mr. Gómez.

Meanwhile, planners here continue to push for more irrigation.

“Because of this water, our children have been able to go to university,” he said. “But if there is no water from the Santa River, that all changes.”