The severe consequences of climate change on our planet are unfolding. Scientists fear that as these impacts get worse and worse, we will stand no chance in saving ourselves and our livelihoods. Last year’s State of the Global Climate by the World Meteorological Organization( WMO) revealed a decade of rising global heat, retreating ice, and record sea levels driven by greenhouse gas emissions from human activities.
According to the report, the five-year (2015-2019) and ten-year (2010-2019) averages of global temperature were the warmest five-year period and decade on record. Since the 1980s, each successive decade has been warmer than the last. In 2019, the researchers found out that large areas of the Arctic were unusually warm. Most land areas were warmer than the recent average, including South America, Europe, Africa, Asia, and Oceania. Both the Arctic and Antarctica also saw record low ice extents in 2019.
“If we do not take urgent climate action now, then we are heading for a temperature increase of more than 3°C by the end of the century, with ever more harmful impacts on human wellbeing. We are nowhere near on track to meet the Paris Agreement target,” WMO Secretary-General Petteri Taalas said.
One of the severe impacts climate change has brought on Earth are marine heatwaves, prolonged periods of anomalously high sea surface temperatures. A 2018 study revealed that global average marine heatwave frequency and duration from 1925 to 2016 increased by 34% and 17%, respectively, resulting in a 54% increase in annual marine heatwave days globally. These heatwaves caused severe impacts on marine ecosystems for the past few years.
Past Marine Heatwaves
According to Nature.com, a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology, scientists recorded notable marine heatwaves in recent years. This includes events that occurred in the northern Mediterranean Sea in 2003, the Western Australian coast in 2011, the northwest Atlantic in 2012, the northeast Pacific over 2013–2015, off southeastern Australia in 2015-2016, and across northern Australia in 2016. Scientists fear that these heatwaves will make a comeback this year.
In 2013, a large marine heatwave occurred in the northeast Pacific Ocean. It was nicknamed the ‘Blob’, after a horror film monster that consumes everything in sight. The large marine heatwave also appeared as a giant red blob on ocean surface temperature maps. It had a significant impact on marine life and fisheries from the coast of Alaska to Baja California―an impact that lasted for years. Eventually, the Blob reached all the way from the Gulf of Alaska to the coast of Mexico from 2014 to mid-2016.
The Blob had several effects during those years, contributing to a global coral bleaching event and impacting coastal salmon fisheries. According to Science Alert, a leading scientific publisher dedicated to publishing peer-reviewed significant research work, delivering quality content, the southern coast of Alaska lost more than 100 million Pacific cod, populations of humpback whales dropped by 30%, and thousands of seabirds were found washed up on the shore. At the same time, salmon, sea lions, krill, and other marine animals vanished in astonishing numbers, as toxic algae bloomed. Previous reports also revealed that starving sea pups started washing up on California beaches in 2015 at more than 10 times the usual rate.
Algal blooms nearly dominated marine waters, causing toxins to accumulate in the bodies of fish and shellfish. These poisoned birds and other predators and closed down fisheries. Whales, feeding closer to shore than usual to find prey, became entangled in fishing gear. The prolonged heat during the 2014-2015 caused bleaching at levels approaching 100% in some places. However, it didn't end there. This year’s marine heatwave could be just as deadly.
The Return of the Blob
Research suggests that blobs and similar events are becoming more common across the world. This year, we might be experiencing one. Scientists from the US National Oceanic and Atmospheric Administration (NOAA) reported that the current heatwave has not only popped up in the same area, but it's also grown in much the same way and is almost the same size. Researchers who tracked the phenomenon last year said that patch of ocean water is now roughly five degrees Fahrenheit above normal―just a degree or two less than temperatures during the last Blob.
According to Mongabay News, a nonprofit provider of conservation and environmental science news, the new Blob might already be contributing to coral bleaching. “Ocean temperatures are extremely warm right now across the main Hawaiian Islands. They’re up to 3.5°F warmer than what we typically experience this time of year. If the ocean continues to warm even further as predicted, we are likely to witness a repeat of unprecedented bleaching events in 2014 and 2015,” NOAA scientist Jamison Gove said in a statement.
Andrew Leising, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, said that the current northeast Pacific heatwave is “on a trajectory to be as strong as the prior event.” NOAA scientists have also learned that the blob and similar events worldwide that what used to be unexpected is becoming more common.
A recent study published in the journal Scientific Reports revealed that previous research had largely underestimated climate change impacts on our marine life as they focused on changes in the average conditions. William Cheung, professor and Canada Research Chair in Ocean Sustainability under Global Change at the UBC Institute for the Oceans and Fisheries, said that the impacts are likely to be doubled in the next few decades when marine heatwaves occur.
According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, the researchers quantified the future impacts of marine heatwaves like the Blob on fish stocks along the west coast of Canada and the US using the latest climate, ocean and fish modeling approaches. The results revealed that the future blobs would exacerbate climate change impacts on fish stocks, causing them to decrease in biomass and generating shifts in their distribution.
Thomas Frölicher, assistant professor at the Physics Institute and Oeschger Centre for Climate Change Research of the University of Bern, said that future Blobs would be occurring more frequently and with higher intensity in the coming decades. "Our results underscore the need for a reduction of anthropogenic greenhouse gas emissions -- the fundamental driver of ocean warming, to limit challenges from marine heatwaves on fish stocks and fisheries,” he said.