Chongqing- It has been 30 years since climate change came to public attention in the 1990s. Still, many people reject this term at first sight of it. Now, harsher than ever, the truth is forced on them as many climate change-induced impacts are already felt in our daily lives.
In recent years, all types of extreme weather have increased in intensity and frequency. That is why we witness heat waves, wildfires, floods, and droughts becoming increasingly common worldwide. For example, overseas, the flash floods in Pakistan have inundated vast areas of this country and displaced more than 33 million people. Domestically, this summer's unprecedented heatwave swept across Chongqing and Sichuan and caused power shortages for months. People who used to be skeptical about this term have radically changed their attitudes, while believers are getting keener to discover the main factors behind the worsening weather.
Meanwhile, the UN chief warned us again about the world "heading into uncharted territory," and the latest UN climate science report shared our concerns, saying, "We are heading in the wrong direction." All these put us under the impression that humans are on track for a potential catastrophe if we don't make ambitious energy transformation goals in the next few years.
To clarify the current situation, a good start is to go back to review the basics. As we all know, the earth's atmosphere is permeable to sunlight, so sunlight can reach the earth's surface, convert to heat and keep us warm. But the atmosphere is not permeable to heat on the earth's surface, so it traps some of the heat and warms the planet. This warming effect is more significant with carbon dioxide (CO2) in the air. That's why greenhouse gases, mainly CO2, are the primary drivers of global warming.
According to data from the World Bank, CO2 emission has been on a steady rise since 1990, and the current level of global warming is estimated to be 1.2 °C. As further global warming increases the risk of passing through "tipping points"—the thresholds beyond which irreversible changes occur to the climate system and will never be fixed even if temperatures are reduced, 193 Parties (192 countries plus the European Union) collectively agreed to keep global warming "well under 2 °C" under the 2015 Paris Agreement.
What is "well under 2 °C" supposed to mean? Even though the Paris Agreement points out 2 °C Celsius as the upper limit for global warming, the agreement also lists 1.5°C as a more desirable target because it significantly reduces the risk of adverse climate in most of the world. The difference may seem like no big deal until you realize that the ice age was only 4°C colder than our current climate. More specifically, the intensity and frequency of extreme weather like heat waves and drought would be far greater on earth at 2 °C of global warming, so the IPCC (Intergovernmental Panel on Climate Change) uses 1.5° C as the legitimate target in its recent climate change-related reports rather than 2°C.
However, the goal of limiting global warming to 1.5 °C is fairly urgent and testing for the world, as it requires halving emissions by 2030 and achieving net-zero emissions by 2050. With the full implementation of mitigation pledges made by countries, keeping global warming below 1.5 °C above pre-industrial levels would still be out of reach. Scientists estimated that global warming would reach about 2.7 °C by the end of the century under current commitments, which is far higher than the desired target and could have catastrophic consequences.
If people are bound to experience a warmer world, we might as well try to picture what happens if the world overshoots the 2 °C target. For example, which areas are the safest from climate change? And which regions, unfortunately, pay for climate change?
There is a near scientific consensus on future scenarios. In a brutally hot world, unprecedented heat waves, massive wildfires, and deadly floods will often come and hit us much harder than they do today. Island countries and coastal cities would disappear under rising sea levels, and people in these places would have to relocate. The ocean would be hotter and more acidic, and some land would become infertile or, worse, deserts, leaving about a quarter of the earth's species extinct. In addition, crops wouldn't be immune to extreme weather so acute food and water shortages would be inevitable.
Today's cities in mild or cold climates are likely to survive but would hardly fare well in a hotter future. For instance, according to the "wet bulb temperature" theory, scorching hot weather and increased humidity would constitute a world where outdoor activities are impossible, resulting in a loss of a quarter of current productivity. That's because people sweat to cool themselves down under certain conditions. The drier and less humid the air is, the faster the sweat will evaporate, therefore the lower people's temperature relative to air temperature. But the sweat-cooling mechanism might become impossible as the earth is mostly an ocean-covered planet and higher temperatures come with accelerated water evaporation. If most people couldn't be functional in terms of economic activity each summer, the world economy would be devastated in the future.
So, drastic measures must be taken to slash carbon emissions if we want to steer away from a depressing future. And countries that emit the most greenhouse gases should shoulder more responsibility. The question is, what countries are they?
From the Top CO2 Emitting Countries chart 1750-2020, we can tell that most wealthy nations are the main contributors to carbon emissions, while low- and middle-income countries generally have lower cumulative emissions. China is, to some extent, an outlier, as the country ranks 2nd among top emitters but drops out of the top 10 in terms of carbon emissions per capita. The country is actually a major electric battery producer & electric vehicle manufacturer and plays a significant role in reducing carbon emissions. In September 2020, China committed to the international community to "achieve carbon peak by 2030 and achieve carbon neutrality by 2060." This means that China, the world's largest developing country, will go from carbon peak to carbon neutral in the shortest time and with the highest reduction intensity in carbon emission in global history.
As mentioned above, current attempts fall short of the efforts needed to reach the climate goals. But how wide is the gap we have to fill? Based on the UN Environment Program's latest Emissions Gap Report, countries' mitigation pledges need to be "four times higher to keep global temperature rise below 2 °C above pre-industrial levels and seven times higher to limit warming to 1.5°C." These calculations sound particularly daunting as the world is struggling with a potential recession.
Indeed, we face a dilemma of balancing a slowing economy and worsening climate change worldwide. With issues like these, people as individuals may think their efforts won't make any difference. But the goals of climate change are to be ditched or be reached remain to be seen, and the truth is that every one of us plays a part in this critical stage.
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