For daily wit & wisdom, sign up for the Almanac newsletter.
As Earth continues to warm, lower solar radiation may ease the heat’s impact—temporarily. Let’s take a look at some emerging weather patterns.
Our Warming Earth
July 2017 had very close to the same average temperature across Earth as did July 2016, which was the hottest month ever recorded. According to the National Oceanic and Atmospheric Administration (NOAA), the average global land and ocean surface temperature for July 2017 was 0.83 degree C (1.49 degrees F) above the 20th-century average of 15.8°C (60.4°F), only 0.05 degree C (0.09 degree F) behind July 2016.
You can see on the map from NASA, below, that nearly every place on Earth was warmer than normal in July, including all of the Americas. NASA also has an interesting animation showing the temperature departures from the normal mean over the period from January 1880 through July 2017. (See animated map here.)
Nine of the 10 warmest Julys on record have occurred since 2005, with July 1998 the only one before the 21st century. July 2017 also marks the 41st consecutive July and the 391st consecutive month (that’s 32 years and 7 months) in which the average global temperature has been above the 20th-century average.
In my view, this is extremely strong evidence that Earth is warmer than it was in the 20th century. And, because solar activity (the driver of our long range forecasts) suggests that temperatures in recent years should have been relatively cool, this represents strong evidence that there is some other factor causing warming—which would be the increase in greenhouse gases caused by human activities.
What Will Happen Next?
I do expect that solar activity over the next 15 to perhaps 50 years will remain low. And if I am correct, this will keep the Earth’s temperatures cooler than they would otherwise be—although still continuing a general year-to-year warming trend. Then, once solar activity returns to near normal levels, temperatures would jump significantly higher—perhaps on the order of 1 to 2 degrees F.
Although based on the current political climate it seems unlikely that we will have taken the actions needed to deal with the increased temperatures on a national level, states like California, New York, and Florida have already started to enact plans to deal with rising seas and other effects of the rising temperatures.
One very important thing to keep in mind is that with technological advances accelerating at an exponential rate, solutions that would be too complex and costly now will be much more effective in the future. Thus I am hopeful that we will find a way to deal with any changes in climate that will enable the continuing advancement of humanity.
What to Watch for this Winter
As solar activity continues to decline toward its minimum in early 2019, temperatures will be much colder than last winter—but still above normal—from Maine southward to most of Florida and westward through the Great Lakes, Midwest, Heartland, and Northern Plains.
With last winter’s weak La Niña most likely to be replaced by a weak El Niño, cold air masses will have difficulty making any prolonged inroads in the northern Plains, Great Lakes, or northeastern states. But they will be able to slide into the Intermountain region, making below-normal temperatures the rule from the Gulf States westward to California and from the Intermountain region westward to the Pacific Northwest.
The winter of 2017–2018 will feature above-normal snowfall in northern and central New England, from the Tennessee Valley westward to New Mexico, and in the central Great Lakes, central Plains, and Intermountain regions.