By Moisha Blechman
Numbers are the indicators of past, present, and future. If you had to choose a number that would have the most significance for your future, what number would you chose? Your bank account? Your blood pressure or age? Stock market numbers?
Climate scientists would say that 400 is that number. A global average of 400 parts per million of carbon dioxide (CO2) in the atmosphere is the number that will tell you more about your future than any other. The consequences are reflected in dramatic changes in rainfall, temperatures, and the weather patterns we once took for granted.
This year looks to become the hottest year on record. As I write this, Paris temperatures reached 103°F, an unheard of number for a city that never needed an air conditioner. Pakistan and India just experienced a heat wave that caused several thousand deaths. Like all animals, people have thermal limits.
Water for people and crops is in crisis all over the world. Every day we read about the impacts of climate change. Drought is estimated to severely limit crop yields in most parts of the United States, with staggering implications for food prices. It may leave the Northeast as the most reliable source of food for a rising population. The weather itself is becoming more erratic and violent.
More than a third of the CO2 emitted is absorbed by the oceans, making them acidic. This change in ocean chemistry is quickly becoming incompatible for most fish. Can you imagine a future where there is no marine life? It is extraordinary that human beings are rapidly changing the chemistry of the atmosphere and the oceans. The number indicating quantity is like a report card on the health of the planet. It is the number to watch more than any other. It is the number controlling our destiny.
In 1955, it occurred to scientist Charles Keeling that, since burning huge amounts of fossil fuels produces CO2, a greenhouse gas, it must be accumulating in the atmosphere. But to prove the accumulation in accurate and precise terms, Keeling invented a means for making that measurement. There is no question about the science of these measurements and their accuracy. Those measurements -- and their influence on the climate -- cannot be denied.
We are talking facts: greenhouse gases act as a blanket keeping solar heat in, and too much CO2 in the atmosphere will retain too much solar heat. These are two facts, and both are easy to understand and undeniable. They should have been repeated in news reporting whenever climate change was mentioned. It would have alerted the wide public about the real gauge to watch, the most consequential gauge telling us about our future. And it would have eliminated both the confusion on the topic, and the possibility of denying man's role in changing the world's chemistry.
There is just one more important concept to understand: how much CO2 may civilization release and still maintain Earth's systems in balance. Scientists call this radiative balance, or the relationship between solar energy retained on Earth, and solar energy released to outer space. Exactly how sensitive is the Earth to increasing greenhouse gases in the atmosphere? What is the limit? This is the number that will describe our future more than any other.
Recording the measurement of CO2 in the atmosphere every day started in 1958 and continues to this day. If you go to CO2now.org you will see the chart tracking these measurements. In 1958, there were 318 ppm of CO2 in the atmosphere. Since then, the CO2 in the atmosphere has increased every year. In 1988 the chart tells us that we hit 350 ppm. This was considered a sustainable amount. The chart goes no further than 400 ppm. That was considered the ceiling beyond which we may not, and would not, pass.
But we have done just that. The CO2 in the atmosphere has reached 403.7 ppm.
When you consider that 280 ppm was normal and gave us a healthy planet for about 12,000 years, it could be that even 350 ppm is too high. The question has always given scientists serious pause. All plants and animals are reacting to increased warmth, increased CO2, and to a changing and unfamiliar environment. We do not really know the upper limit for greenhouse gasses that will maintain a stable and healthy climate for life as we know it. The choice of 350 ppm was made by Bill McKibben. Climate scientist James Hansen said 350 ppm or less, but 350 has been generally accepted as a benchmark which we may not exceed. The penalty for going beyond 350 ppm is already catastrophic for many peoples, and getting worse.
Even a few years ago the managing director of the International Monetary Fund declared: "Make no mistake: without concerted action, the very future of our planet is in peril."
The chart that has tracked CO2 for 57 years has had a ceiling of 400 ppm since its first publication. I suppose the expectation was that we would never reach that point. Perhaps the chart was set up with the knowledge that, at about 400 ppm, the "great extinction," nearly total, occurred 300 million years ago. The news media has failed to confront the “denier” faction with this historical fact.
We are experiencing payback for an era when people's lives were so much more convenient and comfortable. In fact, those who live in the industrial nations have been living in the most comfortable and convenient age in the history of humanity. But it has been at the expense of environmental stewardship and social responsibility. So far, we seem to be unable to accept that the age of excess is over.
The corporations that provide coal and oil enable the public addiction to fossil fuel energy. The frackers and extractors make no concession to the consequences of their relentless drive for profits. Not only are all the coal mines in operation, but Royal Dutch Shell is poised to explore for oil in the Arctic by permission of the Obama administration. At 403.7 ppm of CO2 in the atmosphere, I would call this cultural insanity.
Moisha Blechman chairs the Chapter’s Publications Committee and co-chairs the Climate Crisis committee.