We've already seen three snows this winter season, and we still have the entire (and historically snowiest) month of February to go. Three snows in one season has only happened once before: 1973. Then, a whole generation of Houstonians would add the historic event to their scrap books and life memories. But a fourth snow? That would be a first in Houston's recorded history, dating back to the late 1800s -- and it's possible early next month. Certainly, if you go far enough back in geologic time you could find a year when it's happened in this spot on the planet, but it's absolutely unheard of from the perspective of people actually living here.
This snowy potential is 12 days away, which is too far out to be any kind of 'accurate', but these long-range outlooks do serve as an indication of a colder pattern to come, and of moisture increasing. Will it snow? No guarantees. We'll have a better handle on this by the end of next week. If it happens, the winter of 2017/2018 would be remembered for a very long time.
But, this current colder-than-normal winter, featuring nearly a dozen freezing nights, has reminded me that weather's variability from season-to-season in its natural tendency to be warmer sometimes and cold other times can make or break your garden in Houston, not to mention crops during the growing season. (Raise your hand if all your tropicals were burned beyond recognition by last week's freeze!)
As I was thawing out from the freeze and looking ahead at possible Houston snows in a few weeks, I read an article published yesterday in USA Today and laughed. It discussed 'innovative' ways humans could artificially cool the planet from the harmful effects of global warming, after a study was published by British journal Nature Ecology & Evolution. (Despite this frigid winter in the USA, climatologists insist that most of the planet outside of our region is actually much warmer than normal.) Overwhelming scientific consensus concludes that human-caused climate change is very real, but of course when you're in the middle of a cold winter, the idea of warmer days can be appealing!
To artificially cool the planet, pilots would inject sulfur dioxide (SO2) high into the stratosphere, blocking solar radiation -- exactly like a large volcano eruption would do -- effectively reducing the amount of total sunshine absorbed by our planet and resulting in a measurable cool down. In 1991, when Mt. Pinatubo exploded, global temps dropped nearly 1°F, making for a cooler summer and colder winter. Some climate scientists say using this method of geoengineering is a viable way to, "undo" the warming damage done by our greenhouse gas producing carbon-based industry and transportation.
It sounds neat, but could it cause more damage than it might resolve? What if humans successfully were to accomplish a feat of, "geoengineering" and reduced the global temperature by the 1.53°F we've reportedly warmed since 1880, by adding twice the total sulfur dioxide than Mt. Pinatubo? On the surface that sound advantageous, assuming the warming has been exclusively or mostly caused by humans and not by natural processes like sun cycles or climate oscillations. But, what if a new volcano unexpectedly erupted during our geoengineering efforts and there was a sudden and unwanted surge of SO2, cooling our planet further than planned? Could it cause early frosts, affecting food production and/or the economy? The world has seen a, "Year Without a Summer" in 1816 when Mount Tambora blew in the south Pacific. Summertime corn crops failed in New England and effects were global. What if the sun varied in intensity a bit more than expected in any given year as we've seen in the last, nearly non-existent solar maximum, leading to less solar radiation being transmitted to Earth, cooling us further? What if the computer models, forecasting how much sulfur dioxide we need to pump into the sky are off by a few ticks and we put too much SO2 into the sky? What if in the next few decades the advent of green technology reaches a critical mass for the oil industry, suddenly pricing them out of the market like coal, and additional greenhouse gases go away overnight? (I don't see that happening any time soon, due to the realities of the military/industrial complex.) What if a rogue nation starts a nuclear war and the sky is even further obscured by clouds? (Yes, we may have bigger problems at that point, I know...)
What if, what if, what if. My point is simply we don't know. While it can be argued that human emissions of carbon dioxide and other greenhouse gases since the Industrial Revolution have effectively acted to already geoengineer our climate -- to be warmer -- can attempting to undo the damage do more harm than good? What about crops and animals that have already adapted to a warmer planet? Would sending them back to a climate resembling the icier times of the turn of the century (when the Thames River in London froze) be a benefit?
There are moral and legal questions abound.
As we look ahead to a new year and a potentially, "snowiest winter ever in Houston", it'll be interesting and concerning to talk about taking proactive steps in geoengineering a cooler planet.
-Meteorologist Brooks Garner