Earth Records Hottest Day Ever: Causes, What Lies Ahead

What’s in today’s article?

• Why in News?
• Is 17-degree Celsius Too Warm?
• Impact of El Nino on Rising Global Temperature
• What Lies Ahead?
• What is ENSO (El Nino and Southern Oscillation)?

Why in News?

• July 3 and July 4, have been measured to be the hottest two days for the earth ever.
• The global average temperature on July 3 was measured to be 17.01 degree Celsius. The next day recorded 17.18 degree Celsius.

Is 17-degree Celsius Too Warm?

• A 17-degree Celsius temperature may not appear to be particularly warm.
• But this temperature was not over any one place or region. Instead, this is a measure of the global average temperature for the day, the average over both land and ocean, including the ice sheets in the polar region and the snow of the high mountains where surface temperatures are well below zero degree Celsius.
• Average temperatures over oceans are around 21-degree Celsius, and oceans occupy nearly 70 per cent of the earth’s surface.
• The Antarctic Ice Sheet, where temperatures can easily drop to -50-degree Celsius, covers about 8.3 per cent of earth’s surface.
• The glaciers and ice caps in the mountain are estimated to account for about another 0.5 per cent of the surface.
• Before the 17-degree Celsius mark was breached on June 3, the hottest daily temperature happened to be 16.92-degree Celsius, recorded in August 2016.

Impact of El Nino on Rising Global Temperature

• On July 4^th, the World Meteorological Organisation (WMO) announced the formal onset of the El Nino phase in the eastern equatorial Pacific Ocean.
• The WMO warned that this onset of El Nino could lead to further increases in temperature this year.
• El Nino is an abnormal warming of sea surface waters in the Pacific, off the northwestern coast of South America.
• It is a large-scale climate driver known to have an overall warming effect on the planet.

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What Lies Ahead?

• With the end of a strong La Nina phase that had subdued the global rise in temperatures for the past two years, 2023, right from its start, was predicted to be extremely hot.
• The UK Met Office announced Tuesday that the past month was the hottest ever June for the UK.
• Before that, NOAA of the United States had measured this year’s March to be the earth’s second-warmest ever.
• Canada is battling its worst forest fires ever, while China is in the midst of a severe heat wave.
• The WMO, in its annual State of Global Climate report published in May, had said that it was almost certain that at least one of the next five years (2023 to 2027) would turn out to be the warmest year on record.
• It had further said there was a 66 per cent chance that at least one of these years would also breach the 1.5-degree Celsius threshold.
  • This means average global temperatures in that year would be at least 1.5 degree Celsius higher than pre-industrial times.

What is ENSO (El Nino and Southern Oscillation)?

Image Caption: ENSO Phenomenon

• ENSO is one of the most important climate phenomena on earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe.
• Though ENSO is a single climate phenomenon, it has three states, or phases, it can be in:
  • El Nino:
    • A warming of the ocean surface, or above-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean.
    • It is associated with lower than normal monsoon rainfall in India.
  • La Nina:
    • A cooling of the ocean surface, or below-average SSTs, in the central and eastern tropical Pacific Ocean.
    • It is associated with a comparatively better monsoon rainfall in India.
  • Neutral:
    • Neither El Nino nor La Nina.
    • Often tropical Pacific SSTs are generally close to average.

Q1) What is the Greenhouse Effect in simple words?

The trapping of the sun’s warmth in a planet’s lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface.

Q2) Do Glaciers have a low Albedo?

Bright surfaces, such as glaciers, have a high albedo and thus reflect a lot of the sun’s energy. Dark surfaces, like the ocean, are less reflective and have a lower albedo.

Source: Earth records hottest day ever on July 4: Causes, what lies ahead