Quantcast

Winter Weather Doesn’t Disprove Global Warming

A cold morning sunrise in Enköping, Sweden on Jan. 27, when the temperature reached a low of 13°F. Anders Uhrvik / Flickr

Weather and climate aren't the same. It's one thing for people who spend little or no time learning about global warming to confuse the two, but when those we elect to represent us don't know the difference, we're in trouble.

For a U.S. president to tweet about what he referred to as "Global Waming" because parts of the country are experiencing severe winter conditions displays a profound ignorance that would be embarrassing for an ordinary citizen, let alone the leader of a world power.


To understand the distinction, it's important to know the difference between "global warming" and "climate change." Although the terms are often used interchangeably, there's a subtle difference. Current global warming refers to the overall phenomenon whereby global average temperatures are steadily increasing more rapidly than can be explained by natural factors. Much of the climate change we're already seeing—from increasing extreme weather events to floods and drought to altered ocean currents—is a result of global warming.

That's leading to a range of impacts, "including rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times," according to NASA. That, in turn, affects everything from the food we grow and eat to water availability to human migration.

Both "global warming" and "climate change" refer to average long-term phenomena and effects, whereas "weather" refers to local changes in climate "on short timescales from minutes to hours to days to weeks," such as "rain, snow, clouds, winds, thunderstorms, heat waves and floods," NASA says.

So, what about those record cold temperatures in parts of the eastern U.S. and Canada? To start, global warming is global; it doesn't refer to one specific place. While parts of North America are experiencing record cold, places like Australia are seeing record-breaking heat. Globally, the past four years have been the hottest on record, and the warmest 20 have occurred over the past 22 years.

Several studies show global warming is causing an increasing number of cold-weather events in eastern North America. "Warm temperatures in the Arctic cause the jet stream to take these wild swings, and when it swings farther south, that causes cold air to reach farther south. These swings tend to hang around for awhile, so the weather we have in the eastern United States, whether it's cold or warm, tends to stay with us longer," said Jennifer Francis, research professor of marine and coastal sciences in Rutgers' School of Environmental and Biological Sciences, who co-authored one study published in Nature Communications.

This, according to National Geographic, also means "floods last longer and droughts become more persistent." The study found that "severe winter weather is two to four times more likely in the eastern United States when the Arctic is abnormally warm than when the Arctic is abnormally cold." Winters are also colder in northern Europe and Asia when the Arctic is warm. The opposite is true in western North America, where severe winter weather is more likely "when the Arctic is colder than normal." The effects are more pronounced when Arctic warming reaches beyond the surface, causing disruptions in the stratospheric polar vortex.

Warmer temperatures can also lead to increased precipitation, which falls as snow when temperatures drop below freezing. As a Scientific American article notes, warmer temperatures in winter 2006 prevented Lake Erie from freezing for the first time in history, which "led to increased snowfalls because more evaporating water from the lake was available for precipitation."
Melting ice in the Arctic, Antarctic and on glaciers exposes land or sea, creating feedback loops, as dark surfaces absorb more solar heat than ice and snow, which reflect it. This accelerates warming.

So, no, a cold day where you live isn't evidence that global warming is a "hoax." Scientists worldwide agree: As humans continue to burn fossil fuels and destroy areas that absorb carbon dioxide, like forests and wetlands, the planet's average temperature will keep rising, with undeniable consequences for human health and survival, as well as for the biodiverse life on which we rely.

A study in Science Advances predicts extreme weather events could increase by 50 percent this century if we don't bring emissions under control. It's time to take this seriously.

David Suzuki is a scientist, broadcaster, author and co-founder of the David Suzuki Foundation. Written with contributions from David Suzuki Foundation senior editor Ian Hanington.

Sponsored
On thin ice. Christopher Michel / Flickr / CC BY 2.0

The Russian military is taking measures to protect the residents of a remote Arctic settlement from a mass of polar bears, German press agency DPA reported.

The move comes after regional authorities declared a state of emergency over the weekend after sightings of more than 50 bears in the town of Belushya Guba since December.

Read More Show Less

This year's letter from Bill and Melinda Gates focused on nine things that surprised them. For the Microsoft-cofounder, one thing he was surprised to learn was the massive amount of new buildings the planet should expect in the coming decades due to urban population growth.

"The number of buildings in the world is going to double by 2060. It's like we're going to build a new New York City every month for the next 40 years," he said.

Read More Show Less
Sponsored

Over the past few years, it seems vegan cooking has gone from 'brown rice and tofu' to a true art form. These amazing cooks show off the creations on Instagram—and we can't get enough.

Read More Show Less
The USS Ashland, followed by the USS Green Bay, in the Philippine Sea on Jan. 21. U.S. Department of Defense

By Shana Udvardy

After a dearth of action on climate change and a record year of extreme events in 2017, the inclusion of climate change policies within the annual legislation Congress considers to outline its defense spending priorities (the National Defense Authorization Act) for fiscal year 2018 was welcome progress. House and Senate leaders pushed to include language that mandated that the Department of Defense (DoD) incorporate climate change in their facility planning (see more on what this section of the bill does here and here) as well as issue a report on the impacts of climate change on military installations. Unfortunately, what DoD produced fell far short of what was mandated.

Read More Show Less
The Paradise Fossil Plant in western Kentucky. CC BY 3.0

Trump is losing his rallying cry to save coal. The Tennessee Valley Authority (TVA) voted on Thursday to retire two coal-fired power plants in the next few years despite a plea from the president to keep one of the plants open.

Earlier this week, the president posted an oddly specific tweet that urged the government-owned utility to save the 49-year-old Paradise 3 plant in Kentucky. It so happens that the facility burns coal supplied by Murray Energy Corporation, whose CEO is Robert Murray, is a major Trump donor.

Read More Show Less