We're coming up to the point of no-return on climate change. If nations around the world had agreed on a path of dealing with the problem 20 years ago, then we'd be well on our way to stabilizing the climate. Unfortunately many countries spent stupendous amounts of energy trying to argue and "prove" that climate change wasn't happening.

As it happens, the countries of the "deniers" have seen the greatest incidence of droughts in recent years. Australia has experienced such severe droughts and water shortages, that public opinion swung sharply from denial to being in favour of doing something about climate. The USA has experienced it's eighth year of drought in the south west, but even as the deniers churn their wheels furiously pretending nothing is amis, farmers and those responsible for supplying water to large populations are getting steadily more alarmed. And in China, which has been energetically burning coal on a massive scale, the deserts are now encroaching Beijing, and China, unlike India, is no longer able to grow enough food to feed it's population (which is why it is frantically buying farm land abroad).

Europe by contrast has not seen droughts on anything like the same scale. There was a severe warm season in 2003, but since then the temperature has been more moderate. This is because the members of the EU agreed to cut emissions by as much as they could, and two of the biggest economies, Germany and the UK have made enormous reductions in CO2, thanks to targeted taxes on petrol, carbon trading schemes and civic campaigns to get civilians to be more responsible - people have switched to low energy light bulbs, stopped leaving appliances on standby, bought energy efficient appliances (the EU insists the energy efficiency is listed on each washing machine etc, so consumers can make informed choices) and generally tried to use less fuel. The recession in Southern Europe is having a further effect - people in Greece are switching from cars to bikes to save money, and this pattern is being repeated across the Med, further reducing CO2 emissions. 

Why have the deniers been hurt most?

It's because though some weather systems are global, a lot of weather systems are local.

For example, Brazil and Australia occupy roughly the same latitudes - Brazil reaches from 6°N to 34°S. Australia reaches from 9°S to 44°S. Brazil averages about 4° cooler than Australia, thanks to the Amazon jungle. The hottest it gets is in the northeast where it can reach 38 °C. In Australia the temperature has been known to go higher than 50 °C in some places.

In fact, take a look at the map of precipitation below - all the areas of the sub-tropics (where the winds extract moisture as they rush to the equator) have deserts - apart from South America, which is protected by the Amazon jungle which has modified the local climate and cooled it.

What this means that that though very small countries can't influence temperatures on their own, working in conjunction with their region which forms a larger land mass - EU, USA, Brazil, Australia - they can lower their regional temperatures and protect themselves regardless of what some idiots are doing in other parts of the planet.

There are four greenhouse gasses - carbon dioxide, methane, nitrous oxide and sulphur hexafloride. This article will be concentrating on carbon dioxide.

How the rainforest cools the Amazon

There is an old saying that trees bring rain, and this has a scientific truth to it. Trees suck up water from the ground via their roots, some of which reach all the way down to the water table, and then emit water vapour into the atmosphere through their leaves. This is why if you wrap a bunch of lettuce in plastic, within a day the inside of the plastic will show water beads - it's because the lettuce leaves have been emitting water, which has been trapped by the plastic. In the Amazon jungle, this is happening on a vast enough scale for there to be sufficient water emitted to form mists and clouds, which in turn produces rain - hence rain forest, because of the constant rain generated.

The clouds cool the earth simply by forming a barrier - sunlight is reflected back out into space as it hits the white clouds. The rain also washes CO2 out of the atmosphere by creating carbonic acid, in a process known as weathering, and returns it to the earth.

And of course the trees themselves remove CO2 from the air in the process of photosynthesis, and emit oxygen, which animals breathe in. Plus trees cast local shade, cooling everything under their canopy.

The net effect is to reduce the temperature of the Amazon basin from what it would have been if the jungle wasn't present.

What increases CO2 in the atmosphere?

All animal life emits CO2 into the atmosphere - we breathe in oxygen and expel CO2. It's telling that the human population now numbers over 6 billion, and we also have several billion domesticated animals that we raise for meat, all of whom breathe out CO2. However, because of falling birth rates in Europe and Japan, plus China's one child policy, within about fifty years, the populations of these areas will start to drop (there will be a temporary bulge as old people live longer, but as these big generations pass on, and later generations stabilise at lower birth rates, the total population should drop in Europe, China and Japan). 

CO2 is also emitted by power stations which burn fossil fuels (or even wood), and by cars and planes. Global amounts of CO2 in the atmosphere have been increasing steadily ever since the industrial revolution. Power generated by wind, solar panels and hydro-electricity is CO2 free. Nuclear power plants do not emit CO2 either - but the time for them has passed because after the surface temperature rises above a certain level we are unable to keep them cool and thus safe. If global action on warming had been taken 20 years ago, nuclear power would have played a big part, but it's now too late as the planet has warmed too much. 

Finally volcanoes emit CO2 into the atmosphere whenever they erupt (and we have eruptions on a regular basis all over the planet).

What people can do to reduce CO2 in their region

Most electricity is generated in local power stations, so the first thing to do is reduce your electricity usage (and thus your electricity bill). It simple to replace all light bulbs with low energy ones, and to make sure you don't leave appliances on standby and purchase energy efficient white goods when replacing old ones.  In cold areas, insulating the loft can reduce the amount of heating you need, and in warm areas, growing shade trees strategically and using awnings on the windows can cool homes without requiring too much air conditioning.

People can switch to using smaller cars (or trams or bikes) to get around, and cut down on the amount of travel by plane - thanks to the internet it is possible to skype and video conference and work from home in a way that was impossible 20 years ago. All these things reduce the amount of fuel used.

People can also cut down on meat consumption (the fewer cows consumed, the less CO2 and methane emitted by these animals), and start buying locally grown vegetables that haven't been flown halfway around the world. Better still, start growing your own vegetables. If you do go down this route, try to conserve water by using rainwater traps to collect water than can be used to water your produce.

Finally plant trees. Planting a long lived hardwood tree like an oak can not only cool down your back garden by providing shade, but it sucks out and locks away CO2 for decades (and sometimes centuries, depending on how long it lives). If the residents of an entire city did this, it would cool the entire area considerably.

As for agriculture, it would make sense for farmers in any given region to get together and agree to plant copses of trees and shrubs on any land that can't be farmed - hills, verges, stony land etc, just so the region as a whole increases the amount of foliage in order to create a mild form of the rain effect that the Amazon boasts - the broader and greener the leaves, the more water is released into the air, grasses such as wheat release negligible water compared to an oak tree. 

There is also nothing stopping governments from actively planting trees to soak up CO2 in areas that are unsuitable for agriculture (eg in areas with a lot of hills or mountains).

We know from history that collective tree growing can protect regions - the difference in outcome between the medieval Norse in  Greenland and the Edo-period Japanese is down to the Japanese actively taking a decision to replenish their forests, whereas the Greenlanders cut down all the birch forests to build boats, and within a few centuries had trashed their environment to the point where it couldn't support life and the Norse died out in Greenland. In fact a whole book was written about this called Collapse: How Societies Choose to Fail or Succeed by Jared M Diamond, a professor of geology at University of California.

Conclusion

It's important to remember that human beings have never existed outside of the Ice Age, and because of our long lifespans and the fact that we have only about three generations a century, we don't evolve fast enough to cope with a heating climate. The whole reason Homo Sapiens left Africa in the first place was because it grew too dry and we needed environments that had more water and more foliage - and this all took place while the polar regions continued to be covered in ice - i.e. we were still in an Ice Age. It's less easy to move now (immigration hassles don't you know), and surviving in a climate where the polar regions have no ice will be completely unprecedented - some rich people would have the resources to weather it, but most of us would be left to die. 

Lots of people are resistant to taking action to reduce CO2 in the atmosphere, not because they want to live in a hell where water is scarce and the temperature is blistering, but because they feel someone else should do the heavy lifting to keep them comfortable. Plus they don't want to give up their "conveniences" though it is as convenient to read in a room lit by a low energy bulb as a standard bulb (and produces lower bills).  However, if you don't want to cut down, you can compensate by greening up and growing as many trees as your land can support. The outcome will be the same, and trees are a thing of wonder, providing oxygen and shade and a peaceful aspect for your environment.

The lesson of the Amazon basin is that the more forestation a region has, the more likely it is that that region will not suffer as much as those who have trashed their environments.

You may also like to look at the following related post: Climate Wars