Ripple effects of climate change being seen in Arizona and Florida

Stories from one very dry place and another very wet one show how the ripple effects of climate change can take unexpected and damaging turns.

The dry place is Phoenix, where the Arizona Republic reported last week about ecological problems being caused by, of all things, seabirds.

Specifically, the culprits are two varieties of cormorants, migratory birds which before global warming spent a few months wintering in Phoenix before heading south to warmer temperatures. Now, though, thousands of the birds are living in Phoenix year-round: Climate change has driven up the temperature in winter months to a point where the animals are comfortable.

Cormorants, a federally protected species, also like the city because it offers dozens upon dozens of artificial water bodies in suburban neighborhoods and at golf courses. Many of those lakes and ponds are surrounded by trees in which the birds can roost, and are stocked with fish, the main component of their diet.

So what’s the problem with having these birds around 12 months of the year?

It starts with them doing a number on fish stocks, which has eroded the water quality in lakes and ponds. A cormorant can eat as much as a pound of fish per day, which has decimated fish populations despite increases in fish stocking.

And because many species of fish eat aquatic plant life, having fewer of them has resulted in proliferation of algae and weeds. That, in turn, has led to an explosion in flies and other insects, which breed in the brackish water.

“In the summers, you can’t even sit out on your patio because a hundred flies will swarm you,” a resident of one Phoenix suburb told the Republic. “This is a totally new issue for all of us living here.”

Meanwhile, the birds’ defecation has altered soil chemistry in the areas where they’ve concentrated, killing ground vegetation and diminishing the health of tree stands.

Is this a major ecological problem? Not on the scale of the intense hurricanes or droughts being caused by climate change, but it does show how global warming can set off chain-reaction situations with wide-ranging effects.

And keep in mind, the bird invasion was brought on by only a slight change in winter temperatures: the average over the past 30 years is just 2.5 degrees higher than it was during the preceding 30 years.

Then there’s the wet place, Florida. In the Sunshine State, you might expect that the greatest dangers of climate change would be increasingly strong hurricanes or sea-level rise that threatens to leave huge swaths of developed coastal areas uninhabitable.

But experts are increasingly worried about another potentially devastating outcome: the loss of vast amounts of drinking water that support millions of Floridians.

The main culprit here is the rise in ocean levels, which is pushing saltwater further inland. That seawater is seeping into aquifers through porous limestone bedrock and also pushing into freshwater basins. Most notably, there’s a serious threat of saltwater contamination in the Biscayne aquifer, a 4,000-square-mile shallow basin that provides drinking water to several million people in Miami and elsewhere in South Florida.

Combined with deleterious effects of agriculture — overpumping of water and toxic runoff — the threat of seawater contamination prompted the Florida Department of Environmental Protection to sound a warning this past spring that “existing sources of water will not adequately meet the reasonable beneficial needs for the next 20 years.”

In Nevada, of course, we’re dealing with our own problems related to climate change, notably the drought that is increasingly stressing our water supply, and temperature increases that have sparked a rise in heat-related deaths.

But whether it’s an explosion in bird populations or freshwater contamination or increasingly intense heat waves, these signs all point to the need to urgently address climate change.

Nevada has significant great strides in that respect in recent years, including when voters overwhelmingly approved a ballot question in November to adopt renewable energy standards. And with President-elect Joe Biden soon to take office, a reversal of President Donald Trump’s destructive climate policies will begin this month.

But it’s imperative to keep pressing. There’s no predicting exactly what ripple effects might be on the horizon if global warming isn’t curbed, or how much damage they will cause.