December 1, 2018 – Coyote Gulch

Photo of Lake Powell in extreme drought conditions by Andy Pernick, Bureau of Reclamation, via Flickr creative commons

From The Washington Post (Katherine Hayhoe):

The Fourth National Climate Assessment — the work of 13 federal agencies and more than 350 scientists, including me — is clear: The Earth is warming faster than at any time in human history, and we’re the ones causing it. Climate change is already affecting people, and the more carbon we produce, the more dangerous the effects over the coming century. Nevertheless, many people continue to believe and propagate some misleading myths. Here are the five I hear most frequently.

MYTH NO. 1
Climate scientists are in it for the money.

When the second volume of the National Climate Assessment was released on Nov. 23, Rick Santorum, a Republican former senator from Pennsylvania, took to CNN to proclaim that climate scientists “are driven by the money that they receive.” Former House majority leader Tom DeLay (R-Tex.) appeared on the network the next day declaring the report to be “made by scientists that get paid to further the politics of global warming.”

I was one of the report’s authors. How much did I earn for the hundreds of hours I spent on it? Nothing. Nearly every day, climate scientists are accused of venality. Our other purported sins include fabricating data, selling out to “big green” — which supposedly tethers our grant money to doom-and-gloom findings — and fanning the flames of hysteria to further our nefarious agenda…

MYTH NO. 2
The climate has changed before. It’s just a natural cycle.

Last fall, when the first volume of the National Climate Assessment was released, White House spokesman Raj Shah responded that “the climate has changed and is always changing.” President Trump himself has embraced this position, claiming that the climate “will change back again.” This line is a popular one with people who dismiss climate change by maintaining that we’ve had ice ages before, as well as warm periods, and so the warming we’re seeing now is just what the Earth has always done…

MYTH NO. 3 Climate scientists are split on whether it’s real.

We often hear that climate scientists are split 50-50 when it comes to whether global warming is occurring. “Each side has their scientists,” Senate Majority Leader Mitch McConnell (R-Ky.) told Politico in 2014. Trump echoed that rhetoric on “60 Minutes” this October, telling Lesley Stahl, “We have scientists that disagree” with human-caused global warming.

In reality, more than 97 percent of climate scientists agree that global warming is happening and that humans are causing it. At least 18 scientific societies in the United States, from the American Geophysical Union to the American Medical Association, have issued official statements on climate change. And it’s been more than 50 years since U.S. scientists first raised the alarm about the dangers of climate change with the president — at the time, Lyndon B. Johnson. The public confusion has been manufactured by industry interests and ideologues to muddy the waters.

MYTH NO. 4
Climate change won’t affect me.

We often think the most widespread myth is that the science isn’t real. But according to public opinion polls by the Yale Program on Climate Change Communication , the most prevalent misconception — one that the majority of us have bought into — is that climate change just doesn’t matter to us…

Climate change is a threat multiplier that touches everything, from our health to our economy to our coasts to our infrastructure…

MYTH NO. 5
It’s cold outside — global warming can’t be real.

Whenever a cold snap brings out our winter parkas, there’s a politician or pundit saying, Global warming? Global cooling, more like!

[…]

But cold weather doesn’t rebut the data that shows the planet is warming over climate time scales. Think of it this way: Weather is like your mood, and climate is like your personality. Weather is what occurs in a certain place at a certain time. Climate is the long-term average of weather over decades.

From KUNC.org (Luke Runyon):

The effects of climate change are not far off problems for future generations. They are existential problems for everyone alive today.

That’s one big takeaway from the U.S. federal government’s latest roundup of climate science, the National Climate Assessment, now in its fourth iteration…

In a chapter dedicated to climate change effects in the southwest, climate scientists say “with very high confidence” that warm temperatures are reducing the water content of mountain snowpack and the flows of rivers and streams that depend on snowmelt. The chapter’s landing page features a photo of low water levels at the nation’s largest reservoir, Lake Mead outside Las Vegas, Nevada, a near perfect symbol of the region’s ongoing water challenges.

Lake Mead December 2017. Photo credit: Greg Hobbs

Without coming up with new ways to manage water and cut greenhouse gas emissions, the report’s authors say existing gaps between water supplies and demands in the desert southwest will only continue to grow.

Much of the report confirms and reconfirms what scientists already know. Here are some of the biggest takeaways for the southwest, which the report defines as California, Nevada, Arizona, New Mexico, Colorado and Utah:

Figure 25.1: Temperatures increased across almost all of the Southwest region from 1901 to 2016, with the greatest increases in southern California and western Colorado.23 This map shows the difference between 1986–2016 average temperature and 1901–1960 average temperature.23 Source: adapted from Vose et al. 2017.23. Map credit: The National Climate Assessment 2018

1. “Water security in the United States is increasingly in jeopardy.”

That’s the sentence that greets readers of the report’s third chapter, dedicated to exploring how climate change will stress U.S. water infrastructure…

2. Shrinking snowpack likely to continue

Southern Rocky Mountain snowpack in Colorado, Wyoming and Utah supplies the vast majority of river flows in the Colorado River watershed. And it’s becoming increasingly scarce…

3. We know how to adapt. But can we do it fast enough?

Some parts of the southwest are already showing resilience in the face of a warming climate, the report says…

The severity of southwestern water shortages is largely up to us, as the report notes in its section on how confident climate scientists are in their findings: “The actual frequency and duration of water supply disruptions will depend on the preparation of water resource managers with drought and flood plans, the flexibility of water resource managers to implement or change those plans in response to altered circumstances, the availability of funding to make infrastructure more resilient, and the magnitude and frequency of climate extremes.”