In January 2019, an unusual weather phenomenon hit the US midwest region, plunging temperatures to a record low, bringing day to day activities to a standstill. The harsh weather conditions were attributed to what was termed as the “Polar vortex phenomenon”. Meanwhile, President Trump took the twitter by storm, once again by a tweet which undermined climate change.
While the twitterati erupted against the US President Trump’s view, there is a need to understand the link between climate change and these kind of extreme weather events. Anthropogenic activities resulted in an increase of Greenhouse Gas (GHG) concentration, which increased the average global surface temperature of Earth. The NASA points out the evidence that average surface temperature increased by 1 degree C since the late 19th century, while the business-as-usual (without any measures to combat climate change) scenario will take the temperature rise anywhere between 2 to 5 degree Celsius at the end of this century. Therefore, naturally, climate change is coupled with increased temperatures all over the globe with melting of Arctic and Antarctic ice. But things get muddled when global warming is touted to be the reason behind the life threatening, sub-zero temperatures in the US, which seems contrary to the fact that climate change is predicted to increase the average surface temperature.
The reason for ambiguity is fundamentally due to difference between climate and weather. Weather is the meteorological condition in a given time. Climate is defined as the average meteorological data, essentially a condition over a stipulated period of time (say a season) or a summation of weather over a stipulated period of time. In fact, surface temperature (as mentioned above) take into account the temperature data of least 40 years. It is also to be noted that the 1 degree rise is calculated with the late 19th century as the baseline. The average summer rainfall (march, april & may) in Chennai is less than 20mm while we may even receive 40 mm rainfall or a meagre 5 mm rainfall in any given year (climate-data.org). These anomalies don’t reflect in long term average data as they get evened out due to stability in other years.
Getting back to the polar vortex fiasco, it is an unusual WEATHER event, not a climate phenomenon. So, sub-zero temperatures due to polar vortex are not evidence against global warming and climate change. In fact, this harsh condition may be attributed to global warming. Polar vortex is a wave of cold air which circulates above Arctic region. Certain reports claim that hot jet air streams over the North American Continent interact with the polar vortex, thereby destabilising them and inviting them down south from the Arctic region. Parallely, a complex set of events involving the melting of sea ice in the Arctic is also seen as an underlying course (Source: The Guardian). Though scientists have not absolutely nailed the evidence, there is no denying that anthropogenic activities are messing with the climate system of earth. While we may prepare for manned mission to Mars & self-driving cars, we haven’t understood the climate process completely.
It is decisive that the elected representatives are aware of vulnerability of earth to climate change and forge a pathway to sustainability. Therefore, it is pivotal for the public, voters and the youth to be up to date on such information to demand and script change from various political parties. With crucial elections coming up in India, voters should urge political parties and bureaucrats to expedite climate action and sustainable planning. It’s high time for the global citizen to learn from the mistakes of the US citizens in their last election. As global citizens, the future lies in our hands, world doesn’t have time or answer for another climate change skeptic or a coal industry lobbyist.