WE are in the midst of an epic heat spell, with a warning that extreme heat will be more frequent, intense and prolonged with global warming.

Gone viral via social media in recent days is a post “With the polar temperature hitting 32 degrees, who is going to save the polar bears?” The temperature was recorded by a meteorological station at Banak in the north of Norway (within the Arctic Circle). It was well above the average summer high of around 20 degrees.

There is probably not a more opportune time to read “Brave New Arctic: The Untold Story of the Melting North” by Mark C. Serreze.

In his sweeping tale of discovery spanning three decades, Serreze describes how puzzlement turned to concern and astonishment as researchers came to understand that the Arctic of old was quickly disappearing — with potentially devastating implications for the entire planet. Through his fieldwork on ice caps, glaciers, sea ice and tundra in the Canadian and Alaskan Arctic, the world-renowned Arctic geographer and climatologist ushered in an exciting new age of the Arctic in the midst of deep transformation.

As the author observes at the beginning of the book, “I could not have foreseen that Arctic climate research, once the domain of a small community of scientists with love for snow and ice, would become a centerpiece in the quest to understand the impacts of global climate change that would involve collaboration between thousands of scientists from around the world.”

The Arctic is rapidly thawing due to climate change, and we have to blame ourselves for that.

That the Arctic is at the forefront of climate change can be explained in light of snow cover feedback mechanism. It was believed that the drop in the elevation of the snow line below the level of the plateau surface would raise the reflectivity of the surface (albedo), reducing how much of the sun’s energy is absorbed, further cooling the climate over the plateau, fostering the survival of even more high-albedo snow the next summer.

The whole thing could work in reverse as well — warm conditions lead to less snow and ice, lowering the albedo and favoring more warming.

The human-induced changes are different from how ice ages are accounted for. Using ocean core records, in 1976, James Hays and others presented convincing evidence that the major ice ages and interglacials of the Pleistocene had been “paced” by variations in earth’s orbital geometry called Milankovitch cycles. These variations — the earth’s orbital eccentricity, its obliquity, or the timing of the equinoxes — affect how much solar energy reaches the top of the atmosphere at different latitudes and at different times of the year.

The theory of Milankovitch cycles also recognizes that orbital conditions favoring ice sheet onset (in particular, cool summers over the higher latitudes of the Northern Hemisphere) would then kick in various climate feedbacks to hasten the cooling, albedo feedback being but one of them. It is now known that carbon feedback is a biggie ­— as it cools, carbon dioxide comes out of the atmosphere and is stored in the oceans, further cooling the climate.

Unstoppable change

In the ice cap study the author was involved in decades ago, a weather station was set up on an ice cap to measure air temperature, solar energy fluxes, albedo, and other variables. These were then compared to other measurements collected at stations set up at different distances beyond the edge of the ice cap at a similar elevation. Examining the differences showed how the ice cap was affecting the local climate and how far the effects extended beyond its margins.

In 2016, when, on a whim, the author browsed through satellite images, he found the ice caps he explored more than 30 years ago (probably formed back in the Little Ice Age, about 1650-1850) had nearly disappeared. Back in 1959, the larger cap measured 7.48 sq kms, and the smaller one, 2.93 sq kms.

In 2001, research suggested they are only 62 percent and 59 percent of their 1959 areas. And as of July 2016, the ice caps covered only 5 percent of the areas in 1959. They are just ice patches now.

The climate records are clear. Surface temperatures over the Arctic as a whole are rising twice as fast compared to the rest of the globe. The Arctic is quickly losing its summer sea-ice cover, and wintertime losses are also starting to become prominent. Permafrost is warming and in some areas is thawing. Arctic glaciers and ice caps and the Greenland ice sheet are all losing mass, contributing to sea-level rise.

Recent years have seen unprecedented heat waves over the Arctic Ocean during the autumn and winter. The forces of change seem to be unstoppable. Looking forward, well within this century, perhaps only 20 or 30 years from now, the author says, the Arctic Ocean will be essentially free of its floating sea-ice cover in late summer. Sea ice will hence be but a seasonal feature.

“The meltdown of the North is a clear demonstration that humanity has come to the point where we are geo-enineering our own planet — we have entered the Anthropocene,” the author writes.

The speed of transformation is chilling. As the author observes, even as recently as the early 1990s, the Arctic largely seemed like the Arctic of old. It took a while before the science community (including the author) to fully come around to the inescapable conclusion that the region was being transformed.

Since the dawn of the 21st century, the changes have been coming ever faster and are ever more troubling. “The magnitude and scope of the changes that are unfolding have shaken the science community to its roots. We have entered unchartered waters,” the author declares.

The 2018 winter sea ice maximum in the Arctic was the second smallest on record. There are still many unknowns. For instance, Arctic change is certainly affected by what is happening in lower latitudes, but does the outsized warming of the Arctic — compared to the rest of the globe (Arctic amplification) — affect weather patterns in lower latitudes? Has this already happened? Will thawing permafrost lead to a large release of carbon back to the atmosphere, exacerbating the warming not just in the Arctic but for the planet as a whole?

According to the US National Oceanic and Atmospheric Administration, the global average sea level rose to a new record high in 2017 and was about 7.7 cms higher than the 1993 average, the year that satellite altimeter records began to be available.

Ironically, the warming of the Arctic is very useful.

“One pretty sure thing is that as the Arctic continues to become more accessible, it will be a busier place, with less sea ice opening up shipping routes and making rich stores of oil and natural gas under the Arctic seafloor more accessible. Conflicts may arise,” the author warns.

At the end of the book, the author mentioned Seth Borenstein, a science journalist with the AP, who lamented last year that he’s running out of stories about the Arctic — how many times can a journalist report on what is happening in the Arctic before it becomes so repetitive that people lose interest?