Climate Change Science

The information for this explanation comes from MIT's climate change web - you can find it here.

Ice Cores

The basic data comes from ice cores. A steel tube drills into the Arctic ice. The younger ice is at the top, and as the drill goes deeper it drills into ice laid down thousands then tens of thousands of years ago. When ice forms, it traps air inside. Analysing this, we cnn tell both the levels of gasses in the atmosphere and the temperature around at that time. We can see the pattern over the last 800,000 years:

This shows:
a) that when the level of carbon dioxide went up the temperature rose, and when it went down the temperature fell,
b) the levels of carbon dioxide stayed between 200 and 300 parts per million all that time,
c) today the level of carbon dioxide is 418 parts per million. Unlike anything we have seen for 800,000 years!

Changes at the Industrial Revolution

After the mid 1800s we started to burn fossil fuels - coal, oil and gas in large quantities. These powered our modern way of life. As a result, we poured more and more carbon dioxide into the atmosphere.

Fossil fuels are hydrocarbons. That means that they contain hydrogen and carbon. When we burn hydrocarbons, some of the oxygen in the air combines with the hydrogen to form H2O (water), and some of the oxygen in the air combines with the carbon to make carbon dioxide. At the same time a lot of heat energy is released.

CO2 level controls the amount of heat energy stored in the atmosphere

When the sun's rays reach the earth, some are absorbed as heat and some are relected back out into space. Carbon dioxide reflects some of the escaping heat back to the planet. This keeps us comfortably warm. But too much would cause excess heat energy to be stored in the atmosphere

Today, CO2 level is 418ppm, way over balance

The level stayed between 200 and 300 ppm (parts per million) for 800,000 years. The current level is responsible for storing large amounts of excess heat energy. This causes heatwaves and wildfires in some parts of the world and strong storms, storm surges and flooding in other areas.In 2022 this was responsible for a heat dome over North America which cooked fruit on the trees and roasted shellfish on the rocks, wildfires in Australia and California, heatwaves in the Arctic and Antarctica and floods in Europe, China and South Africa.

Predicted (modelled) consequences of all this extra heat energy are appearing on schedule

This is a complicated situation, and not obvious to all. The problems that were predicted have occurred. There are manu more troubles in the future. Climate change is going to get much more severe.

This is the NASA model showing the excess heat (red=hot, blue=cool). You can see the YouTube video of it here.

The big problems will start when we reach tipping points. These are situations that, once they occur, canot be undone. For example, at the moment the ice in the permafrost tundra around the far north is melting. Once it does, it will release huge amounts of methane (another greenhouse gas) with much more severe consequences.

The effect on nature will be devastating.

Result will affect the food supply

The severe displacement of people, mass movements of starving people and inability to feed everyone would cause a complete collapse of civilised society. In the UK we only grow 60% of what we eat. We rely on those with excess selling us the remainder. What is going to happen if food becomes so short that we cannot buy from abroad?

This is why we need to fight climate change. We cannot stop it, it has already started, but we can avoid the worst.

Fighting Climate Change

Climate change is caused by excess carbon dioxide (see the menu option "Climate Change Science").

To fight climate change we need to stop adding more carbon dioxide to our atmosphere and draw down the excess that is there.

To stop adding more carbon dioxide we need to stop burning fossil fuels (coal, gas and oil). If we do not do this it doesn't matter what else we do.

While we are waiting for politicians to achieve that, and in order to encourage politicians to do the right thing, we need to draw down the excess. Sir David Attenborough says that the best the individual can do is to plant trees.

Which is why (we don't march, we plant trees) and shaftesbury tree group are organising community planting sessions.

People are doing many other things as well.