What happens in India doesn't stay in India. Why this deadly heat wave has a wide reach

Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on ourClimate and Environment page.

On December 29, 1972, mathematician and meteorologist Edward Lorenz presented a talk at the 139th meeting of the American Association for the Advancement of Science in Washington, D.C. The title being: "Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas?"

Though Lorenz was trying to detail the difficulty of weather forecasting, since then, the so-called "butterfly effect" has been used in movies most notably Jurassic Park and television to describe chaos theory, or how one small thing may influence something completely unrelated.

While the flap of a butterfly's wings won't necessarily influence the weather thousands of kilometres away, in the face of our rapidly warming planet, there are plenty of reminders concerning our interconnectivity.

Over the past week, stories have splashed across our computer and television screens about the crushing heat wave that has descended across most of India, and for good reason.

India is no stranger to heat waves. Year after year, the country experiences days of intenseheat ahead of its monsoon season that brings much-needed rains for crops.

But this spring has been much different.

Temperatures have soared to near 50 C across almost the entire country of more than 1.3 billion people.

What On Earth54:04What extreme heat in India tells us about the future

This week on What on Earth with Laura Lynch Channeling eco-anxiety into a force for change Feeling the heat in India How to meet the call to go electric One listener's solution that's become a campaign.

"This heat wave is quite unusual. March has been the hottest in 122 years, pretty much the hottest year ever since we began recording temperatures," Aditi Mukherji, a principal researcher at the International Water Management Institute out of New Delhi told CBC News in an email. "Heat waves are common in India, but never so early. Then, heat waves are [normally] localized, but this time, it is widespread almost all across [the country]."

While it's not yet clear exactly what factors have played a role in this historic heat wave, scientists believe that it's been affected by climate change.

"This is what we expect from climate change," said Raghu Murtugudde, a visiting research scientist at the University of Maryland's Earth System Science Interdisciplinary Center. "The thing to notice is that if you look at the Middle East, Mediterranean region, that has warmed a lot since about 1990. And that wind that blows from that direction over to India, is now warmer by a lot."

Loading the dice

That's not to say there isn't some natural variability that's playing a role. Currently, there is a La Nia event occurring. La Nia is part of a natural cycle called the El Nio-Southern Oscillation,or ENSO, where colder waters persist in part of the Pacific Ocean (the opposite, El Nio, means there is warmer water). This can affect weather patterns around the world.

"La Nia sets up a pressure pattern that brings the cold way, way down into peninsular India," Murtugudde said. "We had a colder than normal winter, as we expect from La Nia. Now we are having much warmer than normal spring because that warm air is funnelling straight down all the way into peninsular India."

Then there's the saying: What happens in the Arctic doesn't stay in the Arctic.

"The other thing that's playing into this is that the Arctic has been much warmer than normal. So when that happens, we also get some forces from the Arctic coming south-eastward into Pakistan and India," Murtugudde said.

"It's a deadly combination of what we call natural variability; things like El Nio and La Nia and anthropogenic warming, global warming. So together they are creating this heat wave, which is unprecedented. But this is what we expect from climate change: It loads the dice."

Impacts across borders

It's not just weather patterns and climate that are interconnected. Heat waves carry with them far-ranging effects, some that have no borders.

The most obvious, of course, is heat-related deaths. While there hasn't been an official count of deaths attributed to this heat wave, the last major heat wave, which occurred in 2015, is believed to have killed 2,500 people in India and another 1,100 in Pakistan. However, that number may be higher, as there has been some concern with the way India reports heat-related deaths.

There's also serious damage to India's already-struggling agriculturesector.

"Wheat crops in major wheat growing belts have been severely affected. The pre-monsoon showers provide the much needed moisture to crops. That was missing, and high heat on top of that made the wheat crop particularly susceptible," said Mukherji.

There have also been significant electricity issues, with rolling blackouts. Aside from people being unable to cool themselves off, the shortagesaffectfarmers who need that electricity to irrigate their crops with electric tube wells and pumps, said Mukherji.

"Food scarcity implications are not clear, as India usually has large buffer stocks of food. If monsoons are also disrupted, and then rice crops are affected (either by droughts or floods), we can expect food prices to rise." she wrote.

"However, so far monsoons are predicted to be normal. There are talks of India restricting wheat exports. India is the world's eighth largest wheat exporter. With the war in Ukraine (fifthlargest wheat exporter), prospects of procuring wheat from the international market looks bleak."

And with two major exporters of wheat suffering, it's likely to be felt right around the world.

More to come

The worst part is that heat waves have already been occurring more frequently than pre-industrial times and are expected to rise.

In the most recent Intergovernmental Panel on Climate Change (IPCC) report, Climate Change 2022: Impacts, Adaptation and Vulnerability, the panel found that "more intense heat waves of longer durations and occurring at a higher frequency are projected with medium confidence over India and Pakistan."

At a city level, the impacts get more significant.

With 1.5 C warming above pre-industrial levels, Kolkata, India, will on average experience heat equivalent to the 2015 record heat waves every year, while Karachi, Pakistan,would see it about once every 3.6 years, the panel wrote.

With 2 C warming, "both regions could expect such heat annually."

The hotter it is in India, the more electricity people use to keep cool. That, in turn, increases electricity demand in a country that relies mostly on coal, one of the worst contributors to climate change. And that in turn exacerbates climate change, not just in India, but around the world. It's a vicious circle that is unsustainable, and especially for the poor.

"When India worries about renewable energy mitigation and so on, it has to also worry about adaptation for the poor people to deal with this daily grind, because they have to just think about the next meal,"Murtugudde said.

"Not the next century or 10 years later. Climate change ishere. The future is here."

Flap, flap, flap go the butterfly's wings.