Climate Change: a brief on the history and status today

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You’d be wrong to think that the keyword in climate change was “change”. It’s “climate” and that frames the enormity of the problem. High school geography taught us that weather is a local phenomenon that can swing in a matter of hours. A city could be sweltering hot in the morning but a hefty afternoon shower will cool things down to the point that it feels like a different place altogether.

On a larger scale the cycling of weather changes through the year is what brings about the seasons. The timely switchover is essential to the way we live and our crop cycles. But to change something as complex and overarching as the planet’s climate system itself is a testament to the influence we exert over our surroundings. The two aspects to this – what we have done and what we can do – have been exploited to muddle the conversation.

The earth’s climate has shifted dramatically several times in the past but that happened before human existence. During the Cambrian era (~500 million years ago) the earth had multiple active volcanoes and with an atmospheric CO2 concentration of roughly 4000 parts per million (ppm), the average ambient temperature could have hovered around 49° Celsius. For context, the average temperature today is more than a third lower at 15° Celsius. This isn’t surprising as the excess CO2 trapped a lot more of the infrared radiation beamed back from the earth at a longer wavelength. The last Ice Age on the other hand lasted from roughly 115,000 to 11,700 years ago when much of the world was buried under metres of ice. It is hypothesised that a series of meteor showers during the Younger Dryas years broke the gridlock and warmed the planet into the Holocene era we’re living through today.

Humans had little impact on atmospheric CO2 till the industrial revolution. From the mid-1800s the proliferation of industry, the IC engine and the use of fossil fuels to generate power led to a sharp increase in CO2 emissions. At the moment atmospheric CO2 stands at just over 424 ppm – the highest ever in recorded human history. It’s not coincidental that 2023 was the warmest year on record (2024 could be worse), that wildfires and cyclones have shot up in frequency and that rising sea levels will swallow entire island nations.

The science could not be simpler: more CO2 emissions means a stronger greenhouse effect and warmer temperatures. This melts the ice caps that hold most of the freshwater reserves and that raises the sea levels. Melting ice also lowers the planet’s albedo – the fraction of incident light it reflects – as the darker soil or water underneath absorbs more of the sunlight. This sets off a vicious loop: a lower albedo warms the atmosphere, which melts more of the ice sheets which lowers the albedo even further.

The obvious answer then would be to quit fossil fuels. Yet, affecting the switch is difficult and despite their zero operational emissions, renewable energy plants still feed into less than 30% of the world’s electricity. Their output fluctuates (except for hydropower) and without energy storage, they cannot be relied upon for predictable power supplies. Adding storage to the mix must keep the tariffs affordable too, although that is increasingly less of an issue. Also the global north’s average energy consumption has historically been much higher – up to a 36X difference per capita between the average American and Indian – and barring a few exceptions, much of its power infrastructure was built on coal. The car until recently was both a necessity and a symbol of freedom in the west – in most parts it still is – but this too was orchestrated by unfettered access to petroleum. Fossil fuels have built much of the modern world (including plastics) while eating into its carbon budget.

The flashpoints at the climate negotiations stem from the urgency with which we must move to zero-carbon alternatives and the resistance this incites from the people and industries that benefit from maintaining business-as-usual. For instance, in 2020 the automotive industry accounted for 5% of Germany’s GDP and employed around 820,000 people, primarily centred around the IC engine. The oil and gas industry is estimated to employ 6 million people directly and over 10X more in indirect jobs. On the other hand the best climate scientists have warned that the world must halve its emissions by 2030 or global warming will breach the 1.5° Celsius threshold and climate impacts could snowball from there on.

The resistance is not always just a refusal to budge. Jobs, revenues and taxes cannot be sacrificed even when faced with the existential threat of runaway extreme weather. Yet the predicament is misused by certain groups to prolong the dependence on fossil fuels even where solar or wind power were feasible options. Fossil fuels also received over $3.3 trillion in subsidies in the 6 years after the seminal Paris Agreement was signed in December 2015. The figure ballooned to $7 trillion in 2022 alone and some argue that it artificially inflates their demand. This is where political will and international finance must assume the driver’s role since technically, the global south is ideally placed to leapfrog to more clean energy and not repeat the mistakes of the west.

Climate change is the biggest challenge of our lifetimes. It’s not screen-friendly like the gritty scenes of war or immediately fatal like a viral outbreak. It’s working in the background but its impacts are mounting fast. Thus the message should be loud and clear by now: the crisis is human-induced and we determine how much worse it gets. To keep our own futures viable, everyday changes at the individual level will be as important as the national policies to decarbonise.

This article is part of a series for Sustainability 100+ S3. Learn More: https://www.sustainability100plus.com/

Moneycontrol journalists were not involved in the creation of the article.