Humans have deferred restraining their fossil fuel emissions for so long that it's nearly impossible to stop global warming from intensifying over the next 30 years. The evidence of human-induced climate change in every region across the globe is irrefutable and some of these changes are already ‘irreversible’ for centuries to millennia, according to the IPCC report. 

The Intergovernmental Panel on Climate Change (IPCC) was set up by the United Nations Environment Programme and the World Meteorological Organisation in 1988. Its main purpose is to provide governments at all levels with scientific information which they can use to develop climate-related policies. The sixth assessment report, compiled by more than 200 scientists over a period of several years and approved by 195 governments is the first in a trio gauging the state of climate change, efforts to alleviate it and to adapt to it. The document, which was described as "a code red for humanity" by UN Secretary-General António Guterres, arrived less than three months before the major global climate summit in Glasgow, UK, which took place from October 31 to November 12, 2021, and where governments had the opportunity to make pledges to reverse course and reduce emissions.

The report identifies that “anthropogenic activities have caused approximately 1.0°C of global warming above pre-industrial levels and if no action isn’t taken, global warming is likely to reach 1.5°C by 2030”. This warming is set to persist for generations, even if zero emission pathways are enforced incontinently. The effects of 1°C global warming are already visible in sea level rise, surge in intensity of heat waves, glacier retreat, coral deaths, more frequent and more severe storms, floods and droughts. According to the report, there will be “no region that will be left unscathed by the impacts of climate change”, with huge human and economic costs that far outweigh the costs of action. Regions like the Mediterranean, Southern Africa, the western United States, the Amazon and Australia will experience increased droughts and fires, which will affect not only the ecosystems but livelihoods, agriculture, and water systems. Infrastructure, transport, energy production and tourism in North America, the Arctic, Europe, the Andes, and more might be hugely impacted by the changes in snow, ice and river flooding. Storms will probably become more severe over most of North America, Europe, and the Mediterranean.

The report points out that the Earth's precious carbon sinks, land and oceans, are at immense risk. They presently perform an astounding service in absorbing the bulk of the carbon dioxide the world emits, but as emissions rise, they will become less effective at absorbing CO2. These land sinks will eventually turn into a source, emitting CO2 instead of sucking it in; for example, the southeast Amazon rainforest is no longer a carbon sink mainly because of deforestation and local warming. This can lead to uncontrolled warming, which will not only affect the world’s climate efforts, but can pose significant food and water security risks to countries in the region, and may lead to irreversible biodiversity loss.

According to Govindasamy Bala, professor of Climate Change, for the first time, the new report clarifies the ‘delicate balance’ between aerosols and GHG emissions and their influence on precipitation by noting that “greenhouse gas warming is partially offset by aerosol cooling.” Greenhouse gas-induced warming leads to intensification of rainfall, but from the 1950’s to 1980’s, there was a drop in global land monsoon precipitation and it was somewhat attributed to human-caused Northern Hemisphere aerosol ejection, which signifies that the aerosol cooling effect overpowered the greenhouse effect during the 30 year period. We don't see any trend in monsoon rainfall in the last three decades, mainly because the effects of GHGs and aerosols are almost balanced. In the coming couple of decades this delicate balance may continue but by mid or end of the century the report predicts that we will see a surge in precipitation, Bala explained.

According to the IPCC, there is a direct link between the surge in global warming and extreme climate changes. At 2°C of global warming, heat shocks are more likely to reach critical forbearance thresholds for biodiversity, i.e. out of the 105,000 species that were studied, it is predicted that 8% of plants, 9.6% of insects and 4% of vertebrates will lose over half of their geographic range at 1.5°C, compared with 16% of plants, 18% of insects and 8% of vertebrates at 2°C. 

Repercussions associated with other biodiversity-related risks, for instance, the spread of non-native species and forest fires, are lower at 1.5°C compared to 2°C of global warming.  Extreme sea level events that used to occur once a century previously could happen every year by 2100. 

Thus, the report ascertains that there will be major benefits to limiting global warming to 1.5°C above the pre-industrial level, but doing so will need “rapid, far reaching and extraordinary changes in all aspects of society”.

Pathways to safety

As reported by the IPCC, around 85% of CO₂ emissions come from burning fossil fuels. It is much easier to stop releasing more CO₂ into the atmosphere than it is to eliminate it, and the more we emit, the further we degrade the ecosystems that naturally soak it up. Therefore, global net CO₂ emissions by humans have to shrink by about 45% by 2030 relative to 2010 levels and reach net zero by 2050. This is actually achievable, contrary to popular belief through mitigation measures in the energy sector. 

About 70–85% of electricity is expected to be supplied by renewable sources in 2050. Shares of nuclear and fossil energy with Carbon Capture and Sequestration/Storage (CCS) are modelled to increase, allowing the share of carbon emitted in the atmosphere to fall and natural gas to generate about 8% of global electricity in 2050. All these mitigation measures will need an annual average investment in the energy system of around $2.4 trillion (at 2010 prices) between 2016 and 2035, representing about 2.5% of the world GDP; however, the cost of inaction and delay will be many times more. 

Following these pathways, the use of coal will be almost negligible by 2050, which might worry Indian policymakers, who are still talking about getting 45% of the country’s electricity from coal around the middle of the century. It's expected that by 2050, about 75–90% of CO₂ emissions from industry will be lower relative to current levels. The IPCC says this can be accomplished through "combinations of new and already existing technologies and practises, including product substitution, electrification, sustainable bio-based feedstock, carbon capture, utilisation, and storage." All this will not only help us tackle the climate change situation but also help us achieve Sustainable Development Goals (SDGs).

As a result of the COVID-19 pandemic, greenhouse gas (GHG) emissions are expected to rise. Because economies have been hard hit, every country is desperate for recovery, which can primarily be accomplished with the current brown economy, which includes using coal, gas, and oil to ratchet up growth as quickly as possible. But the good news is that we have technologies that can disrupt the current fossil-fuel-driven industrial system. We cannot wait for disruptive technologies; rather, we must be disruptive in action or it will be too late. As climatologist Xuebin Zhang says, "the evidence is everywhere, if we don’t act now, the situation is going to get really bad."