Anupama Nair
This year, there were unprecedented heatwaves across Europe and North America. Canada witnessed a record temperature of nearly 49°C. Now Europe is again going through a sweltering climate. Europe and North America from the start of the millennium had been witnessing such temperatures. It is the effect of global warming.
What is global warming? Global warming is an aspect of climate change, referring to the long-term rise of the Earth’s temperatures, mainly from human activities such as burning fossil fuels, that pump greenhouse gases into the atmosphere. The main gases that cause the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic). Global warming is expected to have far-reaching, everlasting and distressing consequences for planet Earth.
Josef Werne, a professor of Geology and Environmental Science at the University of Pittsburgh, stated “We can observe this happening in real time in many places. Ice is melting in both polar ice caps and mountain glaciers. Lakes around the world, including Lake Superior, are warming rapidly — in some cases faster than the surrounding environment. Animals are changing migration patterns and plants are changing the dates of activity”. Scientists project that extreme weather events, such as heat waves, droughts, blizzards and rainstorms will continue to occur more often and with larger intensity due to global warming.
We can see from the start of the millennium, each year from 2014 has been recorded as the hottest year in History. The year 2021, broke all previous records. Most of the countries in Northern Hemisphere, recorded record temperatures in June. A heat dome was created in United States and Canada in June, causing temperatures as high as 47°C. I am not talking about Delhi or Lahore, but Canada, a place where summers are always pleasant.
What is heat dome? A heat dome is formed when the atmosphere acts as a lid or cap and traps hot ocean air beneath it. It is an area of high pressure stuck over a region. According, to the National Oceanic and Atmospheric Administration, heat dome formation is more likely during the La Niña years. This year is unfortunately, a La Niña year. Due to the temperature discrepancy, winds blow dense, tropical western air eastward. That warm air eventually becomes stuck in the jet stream, a circulation of air that travels counterclockwise around the globe, and ends up on the Western Coast of the United States. Heat dome works like a lid on a pot, trapping hot air mass underneath. And this feature is often blamed to be responsible for long-lasting and deadly heat waves around the world. Often a very significant heatwave develops underneath with temperatures well above normal, challenging some heat records.
The heat waves bring in a lot of sunlight and sinking air that heats up as it compresses. Western Canada usually experiences such heat waves in July or August beginning, however this year it had occurred as early as June. Lytton, a town in British Columbia recorded a temperature of 47°C on 28th June this year — which was the highest temperature ever recorded in Canada as per NASA's Earth Observatory. This year, record heat was reported in Europe too. Countries like Denmark and Sweden reported sweltering heat.
As you are aware, countries closer to the equator (zero degrees latitude) have warmer temperatures year-round compared to countries farther north or south of the equator. Countries that are further north in the Northern Hemisphere or south in the Southern Hemisphere experience four seasons and a wide range of temperatures, including significantly colder temperatures in the winter. Because of the Earth's tilt on its axis, the polar regions receive the sun's rays at a slanted angle, however, the equator receives the rays more directly over a smaller area, making the rays more concentrated and hotter.
Extreme weather have engulfed several parts of the world in the last few weeks — Europe and Asia have been ravaged by floods, North America by heat wave and Africa by drought. At least forty countries in Europe, North America, Asia, Oceania and Africa have been hit by devastating extreme natural disasters such as floods, storms, heat wave, wildfires and drought.
Scientists attribute these change in weather patterns to climate crisis aggravated by human actions. “Such extreme weather events are likely to be more frequent and severe”, warned World Meteorological Organization in July this year. “Extreme precipitation has been increasing globally due to human-induced climate change”, stated a new research conducted by the University of California. “In a summer already full of extreme weather, it's the heat waves roasting hundreds of millions of people across three continents – America, Europe and Africa and are confirming a grim climate prophecy for many experts” said a weather expert.
(to be continued….)
