Our speaker last week was Lauriston Muirhead. His talk was about climate change caused by humans. He told us that there is no doubt that there has been natural climate change over the history of the earth. However, this has accelerated since the industrial revolution and in particular since 1900. Fossil fuels such as coal, oil and gas are formed from plants etc that die and decompose. As part of this process, CO2 is stored. When we take these resources out of the ground and use them, the CO2 is released into the atmosphere. CO2 is a greenhouse gas, meaning that the net result is that temperatures rise. There is no doubt that this can also occur due to natural reasons. The issue is that they CO2 is currently being released at such a fast rate that the earth is no longer coping. We know that CO2 levels are increasing because we can take ice core samples that contain bubbles. We can then measure the amount of CO2 in these bubbles and map them against the era in which they were formed. Increasing amounts of CO2 result in:
- Melting snow and ice with the attendant increase of sea levels
- Longer droughts
- More intense bushfires
- More intense rainfall events that occur less frequently
- More energy from CO2 results in weather systems becoming more powerful i.e stronger winds, hotter sun, different rainfall patterns etc
To help fix this, we need to:
- Reduce greenhouse gas emissions
- Increase non-carbon energy alternatives
- Contain population growth
- Extract carbon from the atmosphere by planting more trees and similar activities
- Climate engineering.
There are moral and risk management issues with dealing with this problem. Lauriston was adamant that it’s time to act!