If you are in any doubt that climate change is the biggest issue of our time, then I highly recommend watching the talk given by Prof Robert Watson, the former Chief Scientific Advisor to the UK’s Department for Environment, Food and Rural Affairs (DEFRA), at the American Geophysical Union (AGU) conference last week.
The talk is not too technical, so is understandable to a wide audience. In it, he summarises the latest scientific data on climate change. He covers current trends, future projections and the ways that we must adapt to limit its effects. The outlook is grim. The main points are that global temperatures will almost certainly rise by more than 2°C and so we must plan for increased droughts and storms, sea level rises, reduced crop yields, displaced people and widespread extinction of many species. The way we live is going to look very different in 30-50 years time.
The full video is 1 hour long. You can watch it below, or on the AGU website, where there is discussion on the comments. If you have less time, I have made links that skip to the various sections (see below). Of these, the two that you must watch are the sections on observations and projected changes (less than 7 minutes; 05:00-11:22) and on the 2°C limit and how we will miss it (5 and a half minutes; 30:05-35:22).
Academics see talks like this all the time, but for non-academics watching the video, I hope that you will also take away the following points:
- This is a scientist talking to a load of other scientists. There is no hype, no dramatic music, and no cute baby polar bears. There are only data, graphs and trying to understand what they all mean.
- There has been a huge amount of research into climate change. Each of those graphs represents months, years, or decades of painstaking work. The headlines that make the mainstream news gloss over how incredibly detailed our knowledge of current and past climates is.
- Where there is uncertainty in our understanding, it is acknowledged and discussed. We do not know if the Earth will heat by 3°C or 5°C. But there is very little doubt that man’s activities are the main drivers in the current changes.
Some technical terms are used in the talk. You can look most of them up on Wikipedia or Google. The following definitions may help understanding the two key sections of the video.
- IPCC – The Intergovernmental Panel on Climate Change is a body set up by the United Nations to create reports summarising our latest knowledge on climate change. The last report came out in 2007, the next one is due in 2014.
- Scenarios – The climate of the future depends on changes in economies and populations. We do not know what those will be. So the IPCC reports include estimates for a number of possible scenarios and compare the differences. Those beginning with A represent more human activity and pollution.
- Peer review – The process where studies are sent to other scientists before publication. They check that methods were good and that the conclusions are correct.
- Aerosols – Tiny particles floating in the air. These are pollution, and cause acid rain and breathing problems, so we are trying to get rid of them. But they also reflect sunlight back into space and have kept the climate of the last century lower than it would have been. Temperatures will rise as we clean them up.
Edit 04 Feb 2013: if you found this video interesting/useful, here are links to two others.
- Albert Bartlett’s excellent classroom lecture on Arithmetic, Population and Energy now has over 4 million well-deserved views and demonstrates the power of exponential growth.
- Richard ‘Two-Mile Time Machine’ Alley’s lecture at AGU in 2009 describes the role of carbon dioxide in changing the Earth’s climate both recently and over timescales of millions of years.
- 00:00 – Introduction of speaker
- 02:03 – Talk begins
- 05:00 – Observations*
- 08:31 – Projected changes in temperature and rainfall*
- 11:22 – Sea level rise
- 16:03 – Melting glaciers and sea ice
- 17:48 – Tropical storms and heatwaves
- 19:20 – Effect on biodiversity and extinctions
- 25:37 – Ocean acidification
- 27:02 – Agriculture*
- 28:54 – Conflict
- 30:05 – Aiming for less than 2°C*
- 33:08 – Why we’ll miss the target*
- 35:22 – Global CO2 sources
- 40:07 – Our current trajectory
- 41:40 – What we need to do
- 43:48 – Technological changes
- 45:31 – Biodiversity and ecosystems adaptation
- 47:44 – Political requirements and possible actions
- 48:52 – Geoengineering
- 49:53 – The Future Earth programme
- 52:58 – Conclusions
- 54:41 – Questions
* These are the key sections to watch if you have limited time.
Thanks to Simon Carn (@simoncarn) for tweeting the link to the talk.