If there’s one common aspect that’s binding most parts of the UK and several states in northern India, then it’s heatwaves. While Ireland and the UK are experiencing one of the worst marine heatwave alerts ever recorded, in India casualties are on the rise due to rising temperatures. It’s not surprising to see this phenomena of heat waves swiping across, something which we have been often warned by our scientists.
A marine heatwave refers to an extended period of unusually warm oceanic waters in a specific region or over a large expanse of the ocean. Just like heat waves on land, marine heatwaves are characterised by abnormally high sea surface temperatures (SSTs) that persist for weeks or sometimes even months.
At present, ocean waters around the UK and Ireland are in the grip of one of the most severe marine heatwaves on Earth. Meteorologists have warned that temperatures are up to 4°C above normal for this time of the year in some places. Parts of the North Sea have been put in the category four marine heatwave alerts, considered “extreme” by scientists. According to reports, the North Atlantic ocean has experienced record-breaking high temperatures for the past three months. The average surface temperatures peaked at 23°C on June 17, which is 0.2°C above the previous high set in 2010.
Climate change has increased both the frequency and intensity of marine heatwaves in the last few decades. Greenhouse gas emissions which lead to warming of oceans has increased the intensity of these events. The natural El Nino weather phenomena is another contributing factor in this rise.
Any alert in high temperatures in the ocean above the normal can can have significant impacts on marine ecosystems. Marine heatwaves can lead to coral bleaching, harmful algal blooms, change in ocean currents and even in shifts in species distributions. This in turn can affect fisheries and aquaculture industries, even leading to a decline in tourism and recreational activities.
Marine heatwaves have increased in frequency in the last few decades. According to a study published a few years back, scientists noted that the occurrence of these heat waves in oceans were not just rising in number but also having a deep ecological and socioeconomic impact.
Meanwhile in India, the health minister chaired a high-level meeting in the national capital to review preparedness of public health services for heat waves across the country. The soaring high temperature in the country has led to several people falling sick. In the last one week, deaths due to heat stroke have been reported from several states, including Bihar, Uttar Pradesh, and Odisha.
The Indian Meteorological Department (IMD) has predicted severe to very severe heatwave conditions in several other states including West Bengal, Jharkhand, Andhra Pradesh, Madhya Pradesh, Telangana, Tamil Nadu, to name a few.
Heatwave alerts are declared when the temperature breaches the 40°C mark and is at least 4.5°C above normal seasonal levels. According to the World Health Organisation, a heatwave for India is considered if the maximum temperature of a station reaches at least 40°C or more for plains and at least 30°C or more for hilly regions.
Due to the high temperature and alarming number of heatwave alerts it is or utmost importance for people to consider taking up alternatives for helping the environment. These steps will lead to reduction in the high temperature and healing environment along the way.
Here’s a handy guide on how to take care of yourself during heatwaves. Do read to protect yourself from the scorching heat.
Also Read: Explainer on heatwaves and its impact on India