FAQ - Climate

There are plenty of websites which explain this, so we won’t duplicate it all here. What follows is the briefest summary. Many of the basic terms are explained in the Glossary.

Climate is like weather, but averaged out over time and over a region. So we might have a temperate climate in Britain (as opposed to a tropical climate or an arctic climate), which tells us what the weather is like 'on average'. The weather itself changes from day to day.

Climate Change is a change in the climate of the earth (as opposed to the day to day changes in weather). Climate has changed in the past history of the Earth, but has been relatively stable for the last 10,000 years (since the end of the last ice age). "Climate Change" usually refers to the man-made changes being kicked off by mankind’s actions in burning fossil fuels, deforestation, etc. since the start of the industrial revolution and at an increasing pace ever since.

How does burning fossil fuels cause climate change? The main mechanism is the greenhouse effect. The Earth is kept warm by sunlight. Some of this is reflected into space by the Earth and its clouds, but a lot passes through the atmosphere and hits the Earth’s surface, warming it. The Earth would get hotter and hotter unless it also lost the same amount of heat, and it does this by radiating the heat back into space. Greenhouse gases partially block this outgoing radiation and stop it escaping into space. (They can do this because the outgoing heat is no longer sunlight, it is infra-red radiation like the heat from an electric fire, which the greenhouse gases can absorb and trap). The more greenhouse gases there are in the atmosphere, the more heat is trapped, and the more the Earth heats up.

The greenhouse effect is a simple and natural thing (without it the temperature on Earth would be well below freezing). But by burning fossil fuels we are adding such a large amount of greenhouse gases into the atmosphere that we are pushing the greenhouse effect into overdrive, and causing global warming.

Climate change is more than global warming: it includes sea level rise, ocean acidity, increases in storms, changes in rainfall leading to droughts, etc.

Isn’t there still disagreement among scientists that global warming’s real?

No.

There are vested interests who want to make it appear that there is a big debate going on, but there isn’t, any more than there is serious debate over whether the earth is flat. The tactic of pretending that there is more uncertainty than there is, has also been used by many other groups (for example by the tobacco industry for a long time). Newspapers and TV news reports also like to manufacture 'debates', since arguments make a good story. For a couple of decades these forces confused the issue mightily, but the science is increasingly clear for all to see.

Science works by looking at evidence, and the evidence is overwhelming. Nothing is ever certain in science, but some things are pretty close: for example the fact that the Earth is round. In theory, something may overturn this fact in the future, just as relativity replaced Newtonian physics. (But even then, something that works as well as Newtonian physics isn’t completely overthrown, but rather extended. Newtonian physics is a good approximation to relativity in all everyday circumstances).

What does 'upstream' mean? (or 'ppm', 'permit', 'sequestration' ... )

All these terms are defined in the Glossary.

Why is it so urgent?

This is a vital point. Many people are now aware of climate change, but few people appreciation how urgent it is that we tackle the problem.

The urgency comes from tipping points in the climate system. A tipping point is where something suddenly takes off of its own accord, and becomes hard to stop. Suppose you are pushing a car up a hill. This is hard work, and if you stop, the car wants to roll back. But if you go over the brow of the hill, this is a tipping point. The car wants to run away from you, and the more it does, the faster it goes. It gets faster and faster by itself, and you may not be able to stop it.

A tipping point in climate is methane in Siberia. Methane is a powerful greenhouse gas and there is a lot of it trapped under the tundra in Siberia. If the Earth warms up and the tundra melts, this methane will escape, heating up the Earth more. The more it warms up, the more methane escapes, and the faster the heating happens - it is like the runaway car. But this is not the only tipping point. Another one involves melting icecaps (if they disappear, less sunlight is reflected into space, so the Earth heats up faster), and there are many others.

More tipping points are being discovered all the time, which is why scientists are getting increasingly worried. It’s not so much like pushing a car over the gentle brow of a hill, more like pushing a car off a cliff. We are going over this cliff in extremely slow motion, but if we pass the tipping points it won’t matter - there’ll be no way back.

And we are at or very close to several of these tipping points. That’s why it’s so urgent. If you need convincing, look at www.350.org or www.onehundredmonths.org

Well if it’s so important, why isn’t the government doing anything?

A good question. It appears to be because they are ignorant, especially of science, and because they are weak, and increasingly in thrall to large corporate interests.

Politicians in general are highly negligent in ignoring or minimising the importance of climate change. They will tell you that everything is under control, that it’s being taken care of, don’t worry; while in practice allowing the situation to get beyond dangerous and into critical. See the next FAQ section on Climate Policy.

Is it already too late?

Firstly, beware of this argument as a ploy by deniers. A problem that you can’t do anything about isn’t a real problem (so, they will say, hey, we might as well ignore it and get on with Business As Usual).

The honest answer is that we don’t know. The trouble is that climate change happens slowly (if inexorably). We might not know in our lifetimes.

One prospect, though, is that the evidence continues to mount, the ice all melts, and we will know that we’re heading over the cliff. The full effects will unfold slowly, over decades and centuries, but that will not matter - it will be unstoppable. We would then be living with the knowledge that we might have avoided it but that it’s now too late. If you think about how you would feel in this situation, and how you would face your children, then this is a prospect worth avoiding.