The saying goes that there are no atheists in a foxhole. If so, then after this year’s string of catastrophic natural disasters, there should no longer be any climate-change deniers.
This summer seemed to be the tipping point for extreme effects of global warming – record-shattering rainfall, heatwaves, floods, droughts, and wildfires. Tropical heat in Finland, Siberian tundras ablaze, once-in-a-lifetime snow in Brazil, deadly mudslides in Japan, raging floods in Germany and China. Climate scientists had projected that such extreme weather events were possible, but most of them are unnerved to see them all happening so soon – and simultaneously.
But are all of these recent extreme weather events around the globe just once-in-a-century or millennial events, or rather a sign of things to come? If the world’s nations are unwilling – or unable – to flatten the trajectory of global warming by 2030 and reach net-zero carbon emissions by 2050, the effects to life on the planet will be catastrophic.
Extreme Heat is the New Normal
The Paris Agreement on Climate Change warns that we must keep global warming below 2 degrees Celsius (3.6 degrees Fahrenheit) by 2050 – but preferably no more than 1.5 degrees Celsius (2.7 degrees Fahrenheit). The global atmosphere is already 1.2 degrees Celsius warmer than the pre-Industrial Age temperature average. Yet with so much happening this year, it seems that climate modeling may have underestimated the possibility of a dramatic acceleration of almost simultaneous weather extremes.
In July, the record for the Earth’s hottest recorded temperature was shattered at 128 degrees Fahrenheit (53.3 degrees Celsius) in Death Valley, California. Turkey, Canada, Northern Ireland – even Antarctica – all recorded their hottest-ever temperatures in the past two years, and more such extreme weather events are coming in the next thirty years.
Forests parched by years of drought become tinder for lightning strikes, which ignite huge swathes of land. These wildfires are so intense that they can generate their own self-perpetuating weather systems, with twirling fire-tornadoes and soaring pyro-cumulus clouds, which create dry thunderstorms and lightning strikes, setting off more fires in an endless feedback loop. And intense heat waves can also trigger derecho events – an organized line of severe thunderstorms, tornadoes, and hurricane-force winds across hundreds of miles.
The X-Factor: Shifting Jet Streams?
For decades, climate scientists believed that their projections took into account all possible variables, but this recent spate of extreme weather events seems to indicate that something significant wasn’t being captured in their modelling that could explain why so many rare and freakish weather events were pummeling the planet all at once.
One possibly underestimated variable might be the effect of increasing temperatures on the Earth’s jet streams – fast-flowing air currents that are fueled by temperature variations near the polar and tropical latitudes. Our overheated atmosphere is altering the behavior of jet stream winds, causing storm systems to move more slowly, parking themselves over a location for longer periods of time instead of moving on out to sea. For example, in August 2017, Category 4 Hurricane Harvey stalled over Houston, Texas for four days, dumping forty inches of rain. The following month, two back-to-back Category 5 hurricanes, Irma and Maria, devastated Puerto Rico.
Likewise, this jet stream slowdown can trap a brutal heatwave under a high pressure “dome” that stalls over a region, as happened in the Pacific Northwest (116 degrees Fahrenheit/ 46.6 degrees Celsius in Portland, Oregon) and Canada’s British Columbia (national record-breaking 49.4 Celsius/121 degrees Fahrenheit) back in July. Scientists suggest that the heat dome was spawned by changes in the jet stream in the Arctic, which is heating up faster than any other region on Earth.
Water, Water… But Not Everywhere
As the planet’s atmosphere heats up, it holds more moisture, creating monstrous, slow-moving rain storms. But this buildup of moisture in the lower atmosphere doesn’t fall equally across the globe. Relentless heatwaves around the globe are triggering more and more droughts and wildfires, destroying millions of acres in Siberia, Australia, southern Europe, as well as on the North American continent.
“Fire season” along the US West Coast is now 2.5 times longer than it was in the 1970s. Ninety-five percent of the American west is in drought, with 28% facing exceptional drought. And the drought has led to historic low levels in Utah’s Great Salt Lake, the largest saltwater lake in the western hemisphere, and Lake Powell, the second largest reservoir in the US, both of which have shriveled to 33% capacity.
Hotter and Higher Waters
Like the proverbial frog in slowly boiling water, fish and shellfish in the northern Atlantic have been gradually migrating north to more hospitable latitudes ever since Gulf Stream waters became too warm for them to survive. That’s why the lobster industry south of Cape Cod crashed. Between 1996 and 2014, Rhode Island’s lobster landings plummeted by more than 70% – while Maine’s landings surged by 219%.
But water increases in volume as it heats up, adding to the rise in sea-levels already created by melting glaciers, polar ice caps, and mountain snows. And rising seawater will always creep inland, submerging coastlines, swelling rivers, and tainting freshwater wells and septic systems with salt water.
If we do not reduce our greenhouse gas emissions soon, the globe’s average sea levels will rise by at least 5 feet (1.5 meters) by 2100, threatening the existence of many island nations in the Pacific, as well as major cities around the globe: New York, Miami, Boston, and New Orleans in the US; Guangzhou, Hong Kong, and Shanghai in China; Mumbai, India; Vancouver, Canada; and Osaka, Japan.
Climate Change: The Fifth Horseman of the Apocalypse
In just a few generations, the world will be very different from the one we knew before 2021. Unless greenhouse gas emissions are permanently reduced, massive storms, floods, wildfires, hurricanes, droughts, and heatwaves will just get worse, more frequent, and for longer periods of time, until life on this planet is no longer sustainable. The long-predicted climate crisis is no longer a hypothetical event in the future – we are at the tipping point.
How Do “Greenhouse” Gases Trigger Climate Change?
When the sun’s radiant heat hits Earth, much of it is bounced back into the atmosphere. But when too much fossil-fuel carbon emissions (and other gases like ozone, methane, and nitrous oxide) are released into the atmosphere, they form an absorbent layer above the earth that traps the heat, preventing it from dissipating into the upper atmosphere. The result is just like what happens in a real greenhouse – the heat is reflected back to the earth’s surface.
Over time, this excess heat melts glaciers, polar ice, and snow cover that previously reflected the sunlight, dumping as much as 130 billion tons of water into the ocean each year – in the past thirty years, almost half of the Arctic sea ice has melted. The excess heat also warms up the earth’s air, water, and landmasses to increasingly unsustainable levels, causing droughts, wildfires, sinkholes, torrential rains, flash floods, and erratic changes to the jet stream and ocean currents.
