Many readers will recognize the work of climatologist Michael E. Mann. He is the person who introduced us to the “Hockey stick graph” showing the rapid rise in global temperatures that has happened in the past fifty years. Now, he has brought us new information, which could be important. Fortunately, it sets a somewhat optimistic tone, though it came with some important warning notes.
Mann’s warnings could be summed up by saying we need to act on the climate quickly. Writing before our general election, he wrote that another four years with Donald Trump as president would put the action off too long. That issue, fortunately, is behind us. But even with a new administration, waiting for any length of time is a luxury we cannot afford.
Having given that warning, we can sum up the more optimistic view. CBS recently conducted an interview with guests including Michael Mann and James Hansen on climate change (http://bit.ly/CBS-Mann-interview). Mann said he believed global warming can be stopped. He said that oceans and forests could begin to absorb the excess carbon dioxide (CO₂) within years, if emission are reduced to close to zero.
To understand the problem and what it means, we should look at the CO₂ burden in the atmosphere. CO₂ traps heat from the sun. As the amount of CO₂ has been increased by burning fossil fuels, the heat being trapped has also increased. It takes a long time to heat a planet, so the CO₂ we have will continue to heat the Earth until the amount is greatly reduced. The CO₂ is normally drawn down by rain and growing plants, but conventional wisdom is that it could take centuries for that to happen, while the Earth continues to heat up. Mann believes, however, that if we reduce emissions quickly enough, we can still prevent the worst-case scenario from developing, because scientists may have underestimated the ability of nature to recover.
The unfortunate part of this is that the emissions must be reduced dramatically and very soon. Other statements by Mann warn us plainly about what happens if we fail to do so.
One very big threat we have is the fact that polar ice is melting. The record we can put together of polar ice at different times in the past shows that the ice is melting at a rate unlike anything that has happened naturally. According to James Hansen, if the melting gets too far, with ice sheets disintegrating, it would become impossible to stop their decline at all. The rise would make our coastal cities uninhabitable, and over half of the world’s cities are coastal. The current situation is that the ice sheets are disintegrating already.
On the continuing disputes over science of climate change, one thing Mann said was, “There’s about as much scientific consensus about human-caused climate change as there is about gravity.” That means that disagreement among scientists about whether human-caused climate change is happening, is about the same as a disagreement among scientists over whether gravity exists.
Nevertheless, there is disagreement about climate change, but the real disagreement seems to be about what can be done. Some scientists say we can stop climate change fairly quickly, so things will continue to get worse for only a couple of decades. Other scientists seem less hopeful and foresee a time in which huge numbers of people will have to move away from the coasts and live on higher ground.
Regardless of whether we expect that things will only get somewhat worse than they have been of late or move into a dystopian future, it is safe to say that just about all scientists in the field agree on one other thing. To mitigate the damage of climate change, we have to act very quickly.
There is one more aspect to this that not many people are talking about. We do not know what science will develop over the next thirty years, and we do not know how the technology we currently have will be applied. This is not a matter of technology and big business. It is a matter of understanding the needs of the land and the living things on it. Though we do not know how it will happen, we can be sure that our understanding of such things will develop. That may be another reason to hope.
We will have more about Michael Mann in the next issue of Green Energy Times, which will have a review of his latest book. It is titled The New Climate War.