Sunday, August 18, 2019

Our Changing World--Threats but Also Opportunities

The world is changing.

The second half of the 20th century was warmer than the first half. The 21st century is setting new heat records.

In the arctic, ice is retreating and polar bears are starving. Alaska has record high temperatures. Alaska and Siberia have melting permafrost and forest fires. Looking up the Sami of Norway and Sweden, the information is all about warm winters creating problems for their reindeer herds, ones their grandfathers cannot provide advice about, because they've never seen it so warm.

Aletsch Glacier, Switzerland 2019
Switzerland's Aletsch Glacier in 2019;
It has lost more than 1,300 m. (1421 yards) of length and 200 m thickess since
the 1970s  link

Europe set heat records this summer. I was in Switzerland in June, when temperatures reached the upper 90s. In France it was warmer than that, setting an all time record, 45.1º C (113º). A front brought rain and cooler temperatures as we left, but a second heat wave set more records in July, for example Paris' all time high of 42.6º (108.7º F).

Colorado set records too. In July, Lamar in southern Colorado recorded 115º F , the first time 115º has been reached in the history of the state.

The heat is melting glaciers: Greenland lost enough ice in July alone to raise sea level 0.02 inch (link). Sea level is up 2.7 inches (70 mm) in 20 years (link). That isn't much, but it means that storms and peak tides cause more flooding than they did in the 1990s, and as the melting continues, this will worsten.
California coast
California coast, 1984, beautiful and vulnerable to erosion

Hotter air puts more heat into the oceans. Warmer oceans produce more big storms including hurricanes.

Hotter air moving across the central U.S. means when it encounters a cold front, more intense storms, thunderstorms to tornadoes, will be spawned.

Warmer air holds more water than cooler air, so when that warm air mass cools, it will drop more water on the land, changing rainfall and increasing flooding.

And those are only some of the changes we are seeing. Climate is a complex interacting system that affects plant, animal, and human communities in diverse ways, and they interact, creating more impacts. I'm an ecologist; I love the connections. Whether I like them or not, they are here.

I actually don't mean to speak doom and gloom. We're all afraid of change, but change brings opportunity.

In my case, I'm planting plants native to New Mexico, because they should survive in a warmer Colorado. There are glorious plants native to New Mexico but not Colorado.
pineleaf penstemon
Pine-leaf penstemon (Penstemon pinifolius), a New Mexico plant
that might survive in a warmer Colorado; see its current range: link
Water limits plants in large areas of North America. More water will let them survive and grow bigger.

Of couse, three feet of flood water won't grow land plants until it recedes. On the other hand, studying the Missouri River flooding in 1993, I observed that in the natural communities, the plants were generally stratified: the more flooding-tolerant ones were close to the streams, moving up the slope to flood-intolerant species. So the plants most likely to spend three weeks in standing water are, of that community, the most likely to survive the ordeal. If they don't, there are marsh and swamp plants that can.
Flooded grassland
Flood in a Prairie
The climate is changing and relatively rapidly. It isn't "do we want to adapt?" but "how fast will we adapt?" Your favorite organism may not do well, but some species will certainly benefit. Pests will not be the only organisms to survive in new places. Magnolias, camellias, and begonias will soon thrive north of their traditional limits. New birds may arrive at bird feeders or stay over the winter. Butterflies can be expected to expand their ranges.

Make it an opportunity. For environmental scientists it is an opportunity to see adaptation in action. Historically we interpretted adaptation from existing patterns and small-scale experiments. Right now we can see it happen, across continents. Lots of exciting dimensions to this: is it summer temperature or winter temperature, day time highs or night time lows (etc.) that critically limit the distribution of morning glories or cacti or lizards?

yam, Dioscorea
yam (Dioscorea) seedling, Colorado
For gardeners, it is a chance to grow camellias or other plants generally not thought hardy in your area. The yam (Dioscorea) I planted, well north of its traditional range, has survived for six Colorado winters and seeded into areas surrounding my flower beds. For me gardening is playing with plants, so climate change gives me unfamiliar plants to try. The USDA planting hardiness zones have already been adjusted (current zones link, page showing changes link).

camellia in flower
Camellia, in western Oregon, limited by frost
A greeting card I have cherished since 1975 (graduation) says "Every end is a beginning." Likewise, every change is an opportunity.

Comments and corrections welcome.

We must work to slow the changes in our climate. Absolutely.
But, while doing that, since life is giving us lemons, make lemonade.

Kathy Keeler, A Wandering Botanist

1 comment:

  1. You make a good point. Even if we don't "approve" of human-caused global warming, we might as well take advantage of the changes where we can—as an antidote if nothing else :)