Climate change: Pay now or pay later
The Constant Curmudgeon asked for moderation and good sense about climate change. I agree, but there is a lot of misinformation on both sides to clear away first.
He cites the “70’s ice age prediction,” which was never made in the scientific literature; it was Newsweek and other popular media speculative articles, not science. A misunderstanding on the other side is “Tuvalu Island has been inundated by sea level rise,” which is not true. Measurements since 1880 at tide gauges worldwide show a rise of 8 inches per century. Sea level rise will not accelerate until later this century.
People tend to mention specific weather events to make points about climate, which is not valid. Climate is defined as trends averaged over 30-year intervals or more, long-term in order to average out weather events or cycles like El Nino. Weather is like gaining 6 pounds over the holidays and losing them in the spring. Climate is like gaining 1 pound net per year over 30 years.
The measured fact is that the planet as a whole has been gaining heat energy for more than a century, some decades a little faster and some a little slower. Warming is obviously causing changes, not only polar bears losing summer ice, but changes directly relevant for our lives affecting agriculture, forest health and water management.
For example warming is changing the seasonal accumulation and melting of snowpack in the Sierras and Cascades. As snow levels creep up, less winter precipitation sticks as snow. More important, the fact that spring is arriving sooner causes the snow to melt off earlier and faster, reducing the amount available for summer needs.
The top graph shows the change in measured snowpack at April 1st between 1950 and 1997 due to these effects. Red circles are less snowpack and blue are more. Other dates give similar results. The reservoirs and dams to control flooding and manage our water supply are becoming mismatched at the same time as water demand is rising.
The graph is mostly red reductions, except for the southernmost Sierras. It’s normal for a climate picture to have some exceptions. Those exceptions allow people to mislead by cherry-picking the data. Showing only Oregon and Washington delivers one message, showing only Southern California an entirely different one.
Temperature rise is not the only effect of adding heat energy to weather systems, hence the preferred term “climate change.” Scientists are now working out how the added energy and evaporated water vapor will affect local weather -- clearly global warming will mean something different to Seattle summer stratus versus Buffalo lake effect snow.
The extra heat will probably affect the statistics of the weather, with growing support for the hypothesis that there are more extreme events. Reinsurers, the firms who insure insurance companies, have already added climate change into their risk models based on their own research. These hard-headed businesses cannot afford to wait for a broad scientific consensus on extremes.
We are in an interglacial period that began about 11,000 years ago. The cycling between several ice ages and interglacials is well documented over more than 400,000 years. Global average temperature swung roughly 20 degrees F and atmospheric CO2 cycled between about 200 and 300 parts per million.
CO2 was 275 ppm at the start of the industrial revolution and has rapidly climbed to 395 ppm today. The rise can be traced to fossil fuels because of the radioactive isotope mix.
As we burn fossil fuels, we put carbon back into the atmosphere that was buried 100’s of millions of years ago. CO2 has already risen one-third above an 800,000-year high of 300 ppm.
Humanity is conducting a planetary re-engineering project with significant consequences. Success needs a discussion grounded in engineering terms: tradeoffs, values, cost/benefit, science, risk management and elegance. We are already paying for climate change. Our choice is whether to pay now or later, and how much. The human and financial cost is likely to be lower if we work smart now rather than handling it in crisis mode later.
Bill Ray, of Edmonds, is a computer engineer and an award-winning instructor in marine weather for the U.S. Power Squadrons.