Fundamental climate questions
I was recently asked two fundamental climate questions. Why is atmospheric carbon dioxide (CO2) bad, since plants need it to grow? How could the climate crisis kill the economy?
Atmospheric CO2 is a greenhouse gas, transparent to incoming visible light, but absorbing the radiated infrared energy coming from the planet, heating the air. Concentrations are measured in parts per million (ppm).
Twelve thousand years ago, during the ice age, atmospheric CO2 was 180 ppm, ice three miles thick covered the northern half of our continent, and sea levels were 400 feet lower. Over two thousand years, CO2 levels gradually rose to 280 ppm and stayed relatively stable as the interglacial period began. For 10,000 years, humanity thrived and civilization evolved.
Atmospheric CO2 is 425 ppm today, a level not seen for 8 million years, long before humans, when sea levels were 80 feet higher. Not only is this far outside the range where humanity flourished, but the jump has been rapid, adding 100 ppm in the last 50 years, now growing 2.5 ppm each year. This rate of change is so abrupt, the expressed heat lags CO2 content by a decade, so the heat will continue to increase. CO2 isn’t “bad”, any more than heat is “bad”, but too much of either will kill us.
How can this threaten our economy? The fire threat changed dramatically six years ago, beginning with the Redwood Valley and Tubbs fires. Every summer since has brought massive fires and property destruction. The fire insurance industry is alarmed, and cancelations are rising everywhere. The State has backup fire insurance, but the rates are higher and the coverage is reduced. As heat increases and fires continue, insurance may quickly become unavailable or unaffordable. A similar problem is already happening in Florida, with flood insurance rates up a factor of four. Imagine how such an increase will affect the real estate market. As mortgage defaults increase, the local banking industry will be threatened as well.
Tourism is a huge percentage of our local economy. As roads are closed more often due to increasing fires, as Public Safety Power Shutoff blackouts become more common, as air quality regularly deteriorates during fire season, as water shortages are more common, what effect will that have on tourism?
Another large portion of the local economy is the wine industry. Smoke taint from bad air quality at the wrong time degrades the quality of the resulting wine, and sometimes isn’t even noticeable until after the wine is bottled. In addition, as the planet heats, grape varieties that have thrived in specific local microclimates will no longer be as productive. This is already happening to the wine industry in France. Vineyards may have to be completely replanted with varieties that might be able to thrive in the new climate, costing billions. Alternately, vineyards may abandon the area and move further north. Britain is now hosting vineyards escaping increasing heat on the continent.
Extreme heat waves can kill people, especially in areas not used to such heat. Last summer 600 people died in British Columbia, and 20,000 in Europe. While California avoided extensive heat deaths, the grid almost crashed under increased air conditioner loads.
A hotter climate means stronger and wetter storms. California saw 31 atmospheric rivers this winter, and many areas of the state had flooding and wind damage. Many fields are still too wet to support agricultural activity. The huge snow pack in the southern Sierras threatens to flood communities on the valley floor below. Radically climate makes farming more economically risky, and food more expensive.
Last week, ocean heat broke records, increasing concerns that this summer will be hot and deadly, with a damaging hurricane season. Last year, US climate related expenses hit $500B. These costs will inevitably increase as we continue adding to atmospheric CO2 content, already dangerously high. How often can a community rebuild before going bankrupt, or just getting too exhausted to try again?
If we do nothing, atmospheric CO2 will hit 500 ppm by 2050, a level not seen for 12 million years, when the world was 28°F hotter. The best time to act was decades ago, but fossil fuel corporations, protecting their profits, heavily funded climate deniers, so we wasted the time. The next best time to act is today. What is it worth to leave a habitable planet to our children?
Extreme heat waves can kill people, especially in areas not used to such heat. Last summer 600 people died in British Columbia, and 20,000 in Europe. While California avoided extensive heat deaths, the grid almost crashed under increased air conditioner loads.