Bengaluru: If 2019 saw large number of protests against political and economic changes across the world, it also witnessed an overwhelming number of people taking to the streets to demand action against climate change.
Most well-known among these protesters is, of course, Swedish teenager Greta Thunberg, who inspired a global school walkout campaign, urging world leaders to address the threats of ‘climate emergency’ — a phrase that was voted the Oxford Dictonaries’ 2019 Word of the Year.
Scientists, meanwhile, have thrown up numbers and data needed to quantify the fears of rising temperatures, increasing greenhouse gas emissions and the growing threat of rising sea levels.
Each new scientific finding revealed how reality was much worse than what people thought it to be, and some of the worst projections were found to be only conservative estimates.
ThePrint takes a look at the environmental changes that have taken place this year due to human activities.
Highest CO2 levels, global warming
Atmospheric carbon dioxide (CO2) emissions climbed to a dangerous 415 parts per million (ppm), the highest in 2.5 million years. Sea levels rose by 20 metres and global temperatures were three degrees Celsius warmer. By 2100, the mean sea levels are likely to rise to 67cm.
This is the first time in human history our planet's atmosphere has had more than 415ppm CO2.
Not just in recorded history, not just since the invention of agriculture 10,000 years ago. Since before modern humans existed millions of years ago.
We don't know a planet like this. https://t.co/azVukskDWr
— Eric Holthaus (@EricHolthaus) May 12, 2019
A century ago, in 1910, atmospheric CO2 was 300 ppm, which was then the highest in 800,000 years. More CO2 concentration means more heat gets trapped on the surface of the earth, thereby accelerating the process of global warming.
Scientists at US oil giant ExxonMobil had internally published findings about increasing CO2 emissions nearly 40 years ago, in 1982. But the company had then buried the documents, according to a Pulitzer-winning investigative report by InsideClimate.
The earth also broke the record for consecutive warmest years in recorded history. Earlier this year, scientists had confirmed that 2018 was the fourth hottest year, 0.83 degrees Celsius above the 1950-1980 mean. June 2019 was also the hottest month of June in history.
Ice melts and vanishing glaciers
One of the greatest effects of global warming was seen in Greenland, where melting ice sheets were found to release enormous quantities of methane — the third most potent greenhouse gas after CO2 and water vapour.
Carbon reserves under the arctic ice sheet can convert to methane under certain conditions, and researchers have now confirmed that meltwater from these glaciers pumps dangerous amounts of methane into the atmosphere.
Scientists have also found that the Greenland ice sheet is melting at least seven times faster now than it did during the 1990s, and four times faster than in 2003. On 1 August this year, Greenland experienced its largest ever ice-loss of 12.5 billion tons in one day.
In Antarctica, too, ice is melting six times faster than it did in the 1980s, especially in parts of East Antarctica where ice loss was earlier presumed to be slower. The conditions are no better in West Antarctica. On Christmas Eve, temperatures in the South Pole rose so much that Antarctica saw a 15 per cent ice melt in one day.
According to scientific estimates, over 300 million people are expected to be threatened by rising sea levels and flooding due to ice melt by 2050.
Reports have also found that a third of the ice in the Hindu Kush-Himalayan region will also be lost by the end of this century. The region, known as the ‘third pole’, spreads across eight countries and holds the world’s third highest concentration of ice outside the polar regions.
It was also found that China has been illegally emitting trichlorofluoromethane or CFC-11 — the banned ozone-depleting chemical — into the atmosphere.
Loss of biodiversity, extinctions & food supply under threat
The year 2019 also brought to light just how much microplastics dumped into the oceans have been leading to stunted growth, photosynthesis and oxygen production in the bacteria prochlorococcus, which produces 20 per cent of the world’s oxygen.
The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) had also warned over one million species face the threat of extinction due to loss of biodiversity. The phenomenon has been deemed “unprecedented“.
Scientists also found this year that extinctions are occurring 500 times faster now than the background rate (the pace at which extinctions take place naturally). The last of the Sumatran rhinos died earlier this month, and a global survey found 600 species of plants have become extinct since the 1800s.
Researchers have also found that birds are getting smaller in size due to climate change. Early migration is another phenomenon observed in birds — something which not only threatens the existence of these winged creatures but the lives of other animals that depend on them too.
Additionally, there was a 40 per cent drop in the population of insects.
Similarly, fishes were found to have travelled from existing hotspots to more favourable areas due to changes in oceanic currents because of an influx in freshwater from melting ice. This process has directly started to affect fisheries.
An increase of CO2 in air and a consequent acidification of oceans has also killed aquatic lives and reorganised ecosystems. A lot of attention was paid to marine heatwaves, including in United Nations Intergovernmental Panel on Climate Change (IPCC) report. it cautioned against the increasing risk of cyclones.
Another IPCC report also brought to focus how land degradation and loss of ecosystems have threatened the world’s food supply system. Some of the food items under threat are olives, wheat, coffee, and apples. Studies have shown that fruit production could drop by a third. Scientists have also called for drastic alterations of agricultural practices.
Researchers have identified over a million square kilometres of lost tropical rainforests across continents that could potentially be restored for cultivation purposes.
Polar vortex, fires, and deadly diseases
At the beginning of this year, winter in the northern hemisphere hit record low temperatures as Arctic air from the polar regions blew into Europe and North America. This was caused by a break in the polar vortex phenomenon, which keeps cold air close to the Arctic circle.
The frequency of this phenomenon has been increasing with each passing year. It is now expected that it will bring harsher winters, stronger rains, and hotter summers.
There was also a spate of major fires around the world. Australia has been reeling under heavy bushfires with record high temperatures across the continent. By October, there were nearly 2,000 fires in Brazil, and in August, there were a whopping 30,901 fires affecting the Amazon forest.
The Arctic — the coldest place on earth — was also on fire in July. There were a number of wildfires in Siberia and heat waves in Alaska.
Thawing permafrost in the Arctic regions brings with it diseases that were trapped in ice and which humans have not seen for centuries. Scientists have further warned that the earth is very close to nine climate tipping points that could alter the world in a dangerous and non-reversible way.
Meanwhile, reports have indicated that India suffers the most-pollution related deaths in the world.