Having global temperatures at levels not seen in humanity’s lifetime is scary enough, but the worst news may be how fast the globe is warming. That is truly unprecedented.
Previous major temperature swings took place over tens and hundreds of thousands of years – we’re doing ours in a mere hundred. That means that with previous temperature swings, the planet and every living thing on it had plenty, plenty of time to adjust. This time, we don’t.
A warming planet means that habitat zones are shifting, usually either more toward the poles, or upward. That means if you’re adapted to living in the climate that normally exists at the base of the Rocky Mountains in California, you’re going to have to start moving up the slopes, or north to Canada. Naturally, there’s physical limit to how long this strategy will work! In Australia, they’ve monitored species that have moved southward (toward to pole) as that subcontinent has warmed, until they’ve run up against its edge. As the climate continues to shift, they’ll have no place left to move and will die out.
A couple of recent studies highlight the issues:
- At the current pace of change, 57% of plants (which have a harder time “moving”) and 37% of animals are likely to see a 50% reduction in their habitats by 2080. Which is not far away an a species migration time frame. (source: Nature Climate Change)
- Worse, as the temperature rises, the pace of habitat shifting actually accelerates, which means that the above figures are understatements. (source: Nature Climate Change)
- As an example for a specific species, a study has created an index which tracks the “Mean Temperature of the Catch” worldwide, and found that it is definitely rising significantly. For us humans, this means that the species available for food are changing rapidly, and the bounty that used to exist in our territorial waters has “left the building”. (source: Nature)
And it’s complicated. Although the habitat zone may move as a unit, all the plants and animals don’t – mammals move faster than plants, for example, and the insects in between – so food chains get disrupted and species suffer. Even species that can move may go extinct because their food couldn’t move with them.
Living things can adapt to changing climates in two ways: move, or evolve. With our fast pace of warming, there’s no time for natural selection to do its thing for most species. And with our past pace of warming, even moving is proving to be a short-term solution at best.