Aug 10, 2021
Yes, the climate has always changed, but this time around - it's us.
I am still dumbfounded that even now I still hear people saying that the climate has always changed or we don’t know what is causing the climate to change or that we should take a slow cautious approach.
The reason we know that climate has “always changed” is that geologists and climatologists have been researching the issue for over a century. Since the 1960’s, as technical means improved, we have a much clearer understanding the causes of climate change throughout the history of the Earth - greenhouse gases are the driver of climate change, whether natural or human caused.
We have long known what fossil fuel emissions would do to this planet, but it was always down the road. Nobel Laureate Chemist Svante Arrhenius figured it out in 1896 and in fact, created the first known climate model to predict what could happen.
In 1965, President Johnson’s Scientific Advisory Committee gave him a comprehensive report on the impacts of fossil fuels on the atmosphere. They knew then that fossil fuels were the only major source of CO2. They predicted ice cap melting, and sea level rise. The report stated quite clearly that “By the year 2000 the increase in atmospheric CO2 will be close to 25%. This may be sufficient to produce measurable and perhaps marked changes in climate, and will almost certainly cause significant changes in the temperature and other properties of the stratosphere.” They were close – it’s gone up 20%.
Even Exxon new with absolute certainty that fossil fuel use would lead to warming of the planet by the mid-1970s. They of course went on to say the direct opposite for the next 30 years.
Carbon dioxide levels are now as high as they were 3 million years ago. We lived on a very different planet back then. Sea levels were 28 feet higher than today, enough to drown every major coastal city on the planet. About 120,000 years ago, sea levels were 6 feet higher when global average temperatures were just 2 degrees warmer than today and CO2 levels were just a bit higher than they were 200 years ago (285 ppm compared to today’s 425 ppm).
It took 3 million years for CO2 to decrease to the pre-industrial level of 280 ppm due to geologic processes which extracted it out of the atmosphere. It took two centuries to get back to over 400 ppm, and most of that occurred in the last 60 years. As the 1965 report stated, the cause is us. Volcanism can only account for a very minor amount of that increase. In addition, the rate of increase is unprecedented in the geologic record as far back as can be measured accurately.
Frankly, it scares the crap out of the scientists who study the Earth, mostly because they see their projections become reality much faster than they had predicted even a decade ago.
The 2021 IPCC report pretty much says the same thing. We are on a course to no place good and we are getting there more quickly than anyone thought.
So, what do we do about it? Answer is the same now as it was 40 years ago. Cut greenhouse gas emissions.
Those in favor of doing little or nothing will say that because China and India are the biggest greenhouse gas emitters, why should we be taking the lead, especially because US emissions have been decreasing.
Think about this way - what we buy from China is what we used to make here . We have simply exported the emissions to China which we used to generate domestically. China is the current poster child for dirty power generation, but historically, the US is the largest emitter of CO2, having generated a quarter of all emissions worldwide since 1750.
While we are struggling to build offshore wind installations, China accounted for half of last year’s offshore wind installations. As the biblical saying goes – “first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye.”