Hottest Summer in Northern Hemisphere
As per the National Oceanic and Atmospheric Administration (NOAA), northern hemisphere faced its warmest summer on record in 2020. WMO has also released a report and stated that Earth may temporarily pass dangerous 1.5℃ warming limit.
• The northern hemisphere faced its warmest August, with a temperature departure from the 1.19°C average, besting an earlier record set in August 2016.
• The average global land and ocean surface temperature in August was 0.94 °C above the 20th-century average of 15.6°C. This made it the second-warmest August behind August 2016 in the 141-year record of temperatures.
• The Arctic region — a barometer for temperature changes across the world — faced the largest decline in sea ice in the past 41 years due to global warming. The region warmed at twice the rate as the rest of the world because of anthropogenic greenhouse gas emissions.
• The three-month season between June and August this year surpassed both 2016 and 2019 that were earlier tied for the hottest.
• The increased rate of warming was due to a phenomenon called Arctic amplification trig by increasing GHG emission, where melting ice hastened the process of warming by exposing areas not good at reflecting heat back into the atmosphere, creating a feedback loop between melting ice and rising temperatures.
• Human activities emitted 42 billion tonnes of CO₂ in 2019 alone. Under the Paris Agreement, nations committed to reducing emissions by 2030. But report shows a shortfall of about 15 billion tonnes of CO₂ between these commitments, and pathways consistent with limiting warming to well below 2℃ (the less ambitious end of the Paris target). The gap increases to 32 billion tonnes for the more ambitious 1.5℃ goal.
Impacts on India
• This new record had an imprint of global warming and have impact on India as well, For Instance-Western disturbances resulted in heavy rain in March, April and May and, resulted in locust attacks in Rajasthan which spread as far as Chhattisgarh.
Earth may temporarily pass dangerous 1.5℃ Warming Limit
About: A new report by the World Meteorological Organisation warns that limit global warming to 1.5℃, this century may be exceeded by 2024.
The global average surface temperature from 2016 to 2020 is the warmest of any equivalent period on record, and about 0.24℃ warmer than the previous five years.
Report predicts a continuing warming trend. There is a high probability that, everywhere on the planet, average temperatures in the next five years will be above the 1981-2010 average. Arctic warming is expected to be more than twice that the global average.
Sea levels rose by 3.2 mm per year on average over the past 27 years. The growth is accelerating — sea level rose 4.8 mm annually over the past five years, compared to 4.1 mm annually for the five years before that.
The past five years have also seen many extreme events, e.g.- record-breaking heatwaves in Europe, Cyclone Idai in Mozambique, major bushfires in Australia and elsewhere, prolonged drought in southern Africa and three North Atlantic hurricanes in 2017.
This first overshoot beyond 1.5℃ would be temporary, likely aided by a major climate anomaly such as an El Niño weather pattern. However, it casts new doubt on whether earth’s climate can be permanently stabilized at 1.5℃ warming.
Reason for temperature Increasing: The report also found while greenhouse gas emissions declined slightly in 2020 due to the COVID-19 pandemic, they remained very high — which meant atmospheric carbon dioxide concentrations have continued to rise.
Concentrations of the three main greenhouse gases — carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), have all increased over the past decade. Hence, the threat of global warming amplifies. Current concentrations in the atmosphere are, respectively, 147%, 259% and 123% of those present before the industrial era began in 1750.
There is a dire need to call for urgent actions that can bring changes in the global trends in the long term.
The way forward also includes a range of options such as-stabilize GHG emissions, reduce emissions by 2/3 by 2050, improve energy conservation and efficiency, introduce new regulations, Transportation and building codes, raise price of fossil fuels and establish a carbon tax.