IS THE WEATHER ACTUALLY BECOMING MORE EXTREME?

To answer the question, Saravanan says, it is necessary to understand the differences between weather and climate – “what they are, how we predict them, and what those predictions can tell us.”

He explains:

“Meteorologists define weather as the conditions of the atmosphere at a particular time and place. Currently, researchers can predict a region’s weather for the next week with roughly 80% accuracy. Climate describes a region’s average atmospheric conditions over periods of a month or more. Climate predictions can forecast average temperatures for decades to come, but they can’t tell us what specific weather events to expect.

“These two types of predictions give us such different information because they’re based on different data.”

To forecast weather, meteorologists measure what’s called the atmosphere’s ‘initial conditions’ - the current levels of precipitation, air pressure, humidity, wind speed and wind direction:

“Twice every day, meteorologists from over 800 stations around the globe release balloons into the atmosphere. These balloons carry instruments called radiosondes, which measure initial conditions and transmit their findings to international weather centres. Meteorologists then run the data through predictive physics models that generate the final weather forecast.”

And the end result is just that – a forecast, the probability of a particular weather event occurring. Weather is fundamentally a chaotic system, rendering it impossible to produce perfect predictions. The video features a butterfly flapping its wings to illustrate how even the smallest of disturbances can have a major impact on atmospheric conditions – undoubtedly a nod to the so-called ‘father of chaos theory’, Ed Lorenz.

Saravanan continues:

“Climate prediction, on the other hand, is far less turbulent. This is partly because a region’s climate is, by definition, the average of all its weather data. But also because climate forecasts ignore what’s currently happening in the atmosphere, and focus on the range of what could happen. These parameters are known as boundary conditions, and as their name suggests, they act as constraints on climate and weather..

“Most boundary conditions have well-defined values that change slowly, if at all. This allows researchers to reliably predict climate years into the future. But here’s where it gets tricky. Even the slightest change in these boundary conditions represents a much larger shift for the chaotic weather system.

“For example, Earth’s surface temperature has warmed by almost 1 degree Celsius over the last 150 years. This might seem like a minor shift, but this 1-degree change has added the energy equivalent of roughly one million nuclear warheads into the atmosphere. This massive surge of energy has already led to a dramatic increase in the number of heatwaves, droughts, and storm surges.”

So, what does this all mean? Saravanan sums it up succinctly stating that while weather will always be a chaotic system, shifts in our climate do increase the likelihood of extreme weather events.

The lesson concludes:

“Scientists are in near universal agreement that our climate is changing and that human activity is accelerating those changes. But fortunately, we can identify what human behaviours are impacting the climate most by tracking which boundary conditions are shifting. So even though next month’s weather might always be a mystery, we can work together to protect the climate for centuries to come.”

And if you still need convincing of our collective responsibility to fix what humanity has broken, I’d highly recommend David Attenborough’s A Life on Our Planet - essential viewing for when we next batten down the hatches!