After this past summer’s sizzling heat, many people will undoubtedly welcome the coming of winter in the northern hemisphere. Colder weather, though seasonally temporary, will be refreshing. Australians, though, and others in the southern hemisphere, may not be looking forward to their coming summer.
Globally, July 2019 was the hottest July and month on record. The entire summer in the Northern Hemisphere, where 90 percent of Earth’s population lives, turned out to be the hottest summer on record. The heat records just kept piling up. This left no doubt that the entire planet is warming and now reaching levels felt by millions and clearly affecting life. The Arctic bore the biggest brunt, with Alaska setting all-time heat records and the Greenland ice cap melting at alarming rates (over two days, enough ice melted to cover Denmark with two meters of water).
In addition, a trio of new scientific papers showed that the current warming is unprecedented over the past 2,000 years, that the rate of warming exceeds anything seen in the past two millennia, and that while past climate epochs weren’t globally simultaneous, this current one is. The entire planet is heating.
Science journalists, like the scientists they cover, continued to debate how best to get the scientific news about climate change to a public that—in the United States at least—remains divided on acceptance. They have found that understanding readers’ emotional responses to unwelcome news and drawing on psychologists’ findings about human behavior are as important as the gathering and presenting of the facts.
A study released by the World Weather Attribution found that climate change made the July heat wave in western Europe at least ten times as likely to occur compared with a climate not suffering such increases in greenhouse gases.
Yow, Was It Warm!
In August, the National Oceanic and Atmospheric Administration (NOAA) published its State of the Climate: Global Climate Report for July 2019. Here are some of the findings (NOAA 2019a; NOAA 2019b).
The July 2019 global land and ocean surface temperature departure from average was the highest for July since global records began in 1880 at 0.95°C (1.71°F) above the twentieth-century average.
Nine of the ten warmest Julys have occurred since 2005, with the past five years (2015–2019) ranking among the five warmest Julys on record. July 1998 is the only July from the twentieth century to be among the ten warmest Julys on record.
July 2019 marked the forty-third consecutive July and the 415th consecutive month with temperatures above the twentieth-century average. Julys 2016, 2017, and 2019 are the only Julys that had a temperature departure from average at or above 0.90°C (1.62°F). Climatologically, July is the globe’s warmest month of the year, so with July 2019 the warmest July on record, this resulted in the warmest month on record for the globe.
Regionally, North America, Africa, Asia, Oceania, the Caribbean region, the Hawaiian region, and the Gulf of Mexico had a July temperature that ranked among the ten warmest Julys on record. Africa had its warmest July on record at 1.65°C (2.97°F) above average. This value exceeds the previous record set in 2015 by 0.18°C (0.32°F).
July 2019 marked Europe’s twenty-third consecutive July with above-average temperatures.
Another intense heat wave affected Europe at the end of the month, less than four weeks after the June heat wave.
Paris’s high temperature soared to 108.7°F on July 25, easily surpassing the previous record of 104.7°.
According to the World Meteorological Organization (WMO), Belgium, Germany, Luxembourg, and the Netherlands set new national temperature records. Just as in Paris, Germany’s temperature reached 108.7°F (42.6°C) on July 25, breaking its previous record by 4.1°F. Norway tied its maximum temperature record. In the United Kingdom, the 101.7°F temp on July 25 at the weather station in Cambridge Botanic Garden became the United Kingdom’s highest temperature on record.
In Spain, the station at San Sebatian-Igueldo hit 102.2°F on July 23, the highest temperature observed at that location since records began in 1928.
Warmer-than-average conditions engulfed much of Australia, and New Zealand had its second warmest July ever (after the El Nino year of 1998).
Sea ice also shrank to record or near-record lows. The Arctic sea ice extent set a record low for July. Sea ice was 19.8 percent below the 1981–2010 average according to an analysis by the National Snow and Ice Data Center using data from NOAA and NASA. During July 2019, sea ice loss occurred at an average rate of 40,800 square miles per day, surpassing the 1981–2010 average loss of 33,500 square miles. Only seven other years (1990, 1991, 2007, 2009, 2013, 2015, and 2018) had a daily rate of sea ice loss exceeding 38,600 square miles.
The July 2019 Antarctic sea ice extent was 260,000 square miles, 4.3 percent below the 1981–2010 average and was the smallest July extent in the forty-one-year record.
All in all, the first seven months of 2019 were marked by much-warmer-than-average conditions across much of the world’s land and ocean surfaces. (See map, with most of planet showing red much-above-average temperatures.) Ironically, Americans enjoyed a bit cooler than average temperatures, with much of the contiguous United States and southern Canada experiencing temps at least 1.8°F (1.0°C) cooler than average. Given these temperature observations so far and the global temperature outlook, NOAA says, “It is virtually certain that 2019 will end among the top five warm years.”
“It now appears that July was the hottest month on record for the planet,” climate scientist and CSI Fellow Michael Mann of Pennsylvania State University told the Skeptical Inquirer. “Embedded in that record warmth were unprecedented heat waves in Europe and Asia, a reminder that dangerous climate change isn’t a distant threat. By some measure, it is already here.”
Alaska’s and Iceland’s Rapid Warming
So those are the observations and measurements. Are humans noticing? Yes.
“Alaska has been America’s canary in the coal mine for climate warming, and the yellow bird is singing,” begins an August 18 Associated Press news report from Anchorage by reporter Dan Joling (2019). Anchorage, Alaska’s largest city, hit 90°F for the first time on July 4. That was five degrees warmer than the previous record. What were some of the results of Alaska’s warmest ever temperatures this summer?
“Sea ice melted. Bering Sea fish swam in above-normal temperatures. So did children in the coastal city of Nome. Wildfire season started early and stayed late. Thousands of walruses thronged to shore.” Joling quoted climate scientist Brian Brettschneider of the University of Alaska’s International Arctic Research Center in Fairbanks about the “multiple decades-long increases” in temperature that Alaska is seeing: “It becomes easier to have these unusual sets of conditions that now lead to records.” The good news? Some bumper crops of tomatoes and jalapenos. But Brettschneider sees mostly negative effects. He said at this rate, in fifty years Alaska may look like Idaho.
Iceland is preparing for a world without ice. Iceland’s Vatnajokull glacier has been shrinking year by year, so much so that the earth’s crust, unburdened of the weight, is rising from the sea, draining fjords, shifting sediments, and twisting the town’s sewer pipes. “The glacier is melting so much that the land is rising from the sea,” Adalsteinn Ingolfsson, chief executive of one of Iceland’s biggest fishing companies, told business reporter Liz Alderman of the New York Times (Alderman 2019). When those record temperatures hit western Europe in late July, Reykjavík also recorded its highest temperature ever.
“Climate change is no longer something to be joked about in Iceland or anywhere,” Iceland President Guni Johannesson told the Times. “We realize the harmful effects of global warming. We are taking responsibility to seek practical solutions. But we can do better.”
What can we conclude? We know there have been significant natural variations in the past several thousand years. What about that? Many critics of climate science invoke these fluctuations to argue that what’s happening today has happened in the past, but this is not true. Three new scientific studies give historical perspective.
Three New Scientific Studies
An international group of scientists led by climate scientist Raphael Neukom (2019) of the University of Bern reconstructed the climates of the past two millennia in a new study drawing upon tree rings, ice cores, lake and ocean sediments, corals, cave deposits, and historical documents. This international consortium of scientists, called “Pages 2k Consortium,” combined these records with direct measurements collected since the 1800s to produce 15,000 reconstructions of global temperature. They looked at the precise timings of periods of earlier climate epochs, or prolonged fluctuations: the Roman warm period from CE 1 to 300, the Dark Ages cold period from 400 to 800, the Medieval Climate Anomaly from 800 to 1200, and the Little Ice Age from 1300 to 1850. They used many different methodologies and calculations to process the data and determine past temperatures.
No matter the methods used, the results were the same: These past climate epochs were not simultaneous, global events. They varied over time and place, with centuries separating warming (or cooling) in one place from warming (or cooling) in another. For instance, they found that the coldest epoch of the past millennium—the “putative” Little Ice Age—is most likely to have experienced the coldest temperatures during the fifteenth century in the central and eastern Pacific Ocean, during the seventeenth century in northwestern Europe and southeastern North America, and during the mid-nineteenth century over most of the remaining regions. So it’s not the case that these past epochs were simultaneous. They say this lack of spatial-temporal coherence means that preindustrial (natural) forcing was not sufficient to produce globally coherent temperature extremes. By contrast, they find that the warmest period of the past two millennia occurred during the twentieth century for more than 98 percent of the globe. (This study ended at year 2000, so it doesn’t even factor in the rising heat of the past two decades.)
“This provides strong evidence that anthropogenic global warming is not only unparalleled in terms of absolute temperatures, but also unprecedented in spatial consistency within the context of the past 2,000 years,” the study’s authors say. This study was published in the July 25 Nature.
In contrast, the current warming of the planet is occurring concurrently around the globe. “It is coherent in a way we didn’t experience over the past 2,000 years,” says study coauthor Nathan Steiger of Columbia University. He is quoted in an article on these findings titled “Current Warming Is Unprecedented” by Earth and Climate Editor Carolyn Gramling (2019) in the August 17 Science News.
The Pages 2k Consortium’s (2019) own report based on seven of the same data reconstructions was published in the August 2019 Nature Geoscience. The consortium authors attribute many of the climate fluctuations from 1300–1800 to effects of aerosols (particles and gases) spewed into the atmosphere from major volcanic eruptions during those times. All in all, they found, “the largest warming at timescales of 20 years or longer occur during the second half of the twentieth century, highlighting the unusual character of the warming in recent decades.”
A third study, by Stefan Brönnimann, also of the University of Bern, and eleven colleagues (Brönnimann et al. 2019) and also published in the August Nature Geoscience goes into the history of volcanic eruptions in some depth. It concludes that the last phase of the Little Ice Age was extended by major volcanic eruptions in 1808 or 1809 and in the 1820s and 1830s. These kept temperatures cool until anthropogenic warming from the industrial revolution took over. These recently published scientific studies led Michael Mann, who was not involved in any of them, to state: “The current period of warmth is unprecedented in its global scope in the last 2,000 years” (quoted in the August 17 Science News article).
Science Journalists and Climate
Science journalists have been reporting on the science about our warming planet while struggling with the resistance they continue to receive from some climate naysayers. The Summer/Fall 2019 issue of ScienceWriters, the magazine of the National Association of Science Writers (of which I am a lifetime member), devotes its cover article to “Reporting on Climate Change: The Good, the Bad, and the Ugly.” A recent panel on the subject drew standing-room-only crowds. It is summarized in a piece in which science journalist Ann Parson (2019) interviews Woods Hole NPR affiliate reporter Heather Goldstone, creator of the blog Climatetide. Goldstone has found that noticeable climate change is upon us. For instance, commercially exploited marine species have moved north in response to warming temperatures. And she has seen the beach erosion from sea-level rise and the more powerful storms that a changing climate brings. Parsons introduces the piece by noting that she’d just learned that Indonesia had decided to move its capital to another location because of the bad flooding and sinking ground Jakarta was experiencing.
“What the science shows,” Goldstone says in response to one question, “is that if a story evokes certain emotions, it can actually impede a person’s ability to absorb the facts, the information.” Fear is paralyzing, she notes, and the brain’s response is to shut it out and ignore it. She also notes the research of Dan Kahan at Yale University, which we have reported on in these pages, showing that group identities are powerful cohesive forces for humans, and those allegiances determine how we respond to new information. When we ask people about climate change, they don’t respond according to the latest science but according to which political and cultural identity they feel allegiance to (Parson 2019).
Journalists have learned not to constantly hit people over the head with the scientific data showing warming is happening at alarming rates globally but to focus on stories that show direct, local effects on individual lives. And also, to give some hope that positive things can still be done.
In the meantime, enjoy this coming winter, folks. Another hot summer is likely to follow.
- Alderman, Liz. 2019. A world without ice? Iceland is preparing. New York Times (August 12): B1, B4–B5.
- Brönnimann, S., et al. 2019. Last phase of the Little Ice Age forced by volcanic eruptions. Nature Geoscience 12 (August): 650–656. Published online July 24. doi: 10.1038/s41561-019-0402-y.
- Gramling, Carolyn. 2019. Current warming is unprecedented. Science News (August 27): 6–7. Available online at https://www.sciencenews.org/article/global-warming-today-unlike-last-2000-years-climate-shifts.
- Joling, Dan. 2019. Blooms, beasts affected as Alaska records hottest month. Associated Press (August 17, updated August 18).
- Neukom, R., et al. 2019. No evidence for globally coherent warm and cold periods over the preindustrial Common Era. Nature 571 (July 25): 550–554, doi: 10.1038/s41586-019-1401-2.
- NOAA National Centers for Environmental Information. 2019a. State of the Climate: Global Climate Report for July 2019; published online August 2019; retrieved on August 27, 2019. Available online at https://www.ncdc.noaa.gov/sotc/global/201907.
- ———. 2019b. Assessing the Global Climate in July 2019; published online August; retrieved on August 27, 2019. Available online at https://www.ncei.noaa.gov/news/global-climate-201907.
- PAGES 2k Consortium. 2019. Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era. Nature Geoscience 12 (August): 643–649. Published online July 24. doi: 10.1038/s41561-019-0400-0.
- Parson, Ann. 2019. Reporting on climate change: The good, the bad, and the ugly. ScienceWriters Summer/Fall: 14–16.