The sixth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC) has rung the alarm bell for humanity's existence. Considered the largest ever such report, with inputs from over 14,000 scientists and eight years of work, it has boiled down to one message -- humanity is facing an immediate threat posed by the deepening climate crisis, and we seriously have no time to waste.
It is the time for action, warns the IPCC report made public on August 9.
Every part of the planet is witnessing the wrath of extreme weather events; seas and the atmosphere are warming at an unprecedented rate in human history. Moreover, some of the consequences of human activities have caused irreversible changes in the Earth's climate.
The IPCC report has alarming predictions for India as well. The report says that the South and Southeast Asian monsoon has weakened in the second half of the 20th century. In the long term, the report predicted with medium confidence that the summer monsoon precipitations will increase over time. The increase of aerosols in the atmosphere due to human activities has also interfered with India's rainfall patterns. The weakening of the monsoon in the 20th century is attributable to the atmospheric aerosols.
According to Swapna Panickal, one of the authors of the IPCC report and a scientist at the Indian Institute of Tropical Meteorology, the sea temperature is heating at a higher rate in the Indian Ocean than in other areas and therefore may influence other regions. The South West Monsoon has declined over the past few decades because of the increase of aerosols, but once this reduces, we will experience heavy monsoon rainfall.
The sea-level rise will mainly affect the coastal regions, which will witness it throughout the 21st century. The mean sea-level rise of the Indian Ocean is estimated to be 3.7 mm per year.
The report also has a warning for the Himalayas; it says that glacier melting will intensify, and this phenomenon has become irreversible. The report says that in the Indian subcontinent, heat extremes have increased while cold extremes have decreased; this trend is likely to continue for the coming decades.
Further, the report warns that the only way out is a drastic reduction in greenhouse gas emissions within this decade to help prevent the global temperature from rising to a disastrous level.
The IPCC, formed in 1988, is the body of the world's leading climate scientists and has been tasked to prepare comprehensive reports on the state of the climate. Since its first report in 1990, the IPCC has been producing such climate reports every seven years. The sixth assessment report, published on Monday, is the first part dealing with the existing knowledge of the physical basis of climate change. The physical basis is the core underlying science about climate change. The report has two more parts -- one is on the impacts of the climate crisis and the other on the ways to reduce the effects. These two parts will be published by next year.
The report says that within the next two decades, global temperature will rise over 1.5 degrees Celsius above the pre-industrial period, and that is the benchmark set in the Paris agreement. This will bring in devastations and further extreme weather events. Even a fraction of a degree of temperature increase will compound the effects on climate.
The analysis, made upon the physical basis of climate change, represents the complete knowledge about the climate to date. It declares that human activity is unequivocally the cause of disastrous changes in the climate, including the rise in sea levels, melting of the polar ice and the glaciers, floods, storms, droughts, and terrible heat waves.
The UN Secretary-General, Antonio Guterres, termed the findings as 'code red for humanity'. "The alarm bells are deafening, and the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk," the UN Secretary General commented.
Guterres urged that there should be no coal plants any further. "This report must sound a death knell for coal and fossil fuels before they destroy our planet," he said.
The temperature has now risen by 1.1 degrees Celsius than it was during the period of 1850 to 1900. Stabilising the global temperature at 1.5 degrees Celsius was still possible, the IPCC report said. In that scenario, a rise in the temperature of about 1.5 degrees Celsius would increase intense heatwaves, intense storms, severe floods, and droughts. However, stabilising the climate at this temperature would represent a risk much smaller than a 2-degree Celsius rise in temperature.
Richard Allan, the lead author of the IPCC and a climate scientist at the University of Reading, said, "Each fraction of a degree of warming is crucial". He added, "You are promoting moderate extreme weather events to the premier league of extreme events [with further temperature rises]."
The report warned that even if the world successfully retains warming to 1.5 degrees Celsius, there have already been some long-term and irreversible impacts on the climate. The rise in sea levels, Arctic ice melting, warming of the oceans and concomitant acidification of the ocean water are some of the impacts of climate change that have reached the point of no return.
If the world community can manage to cut emissions drastically, that will prevent worse climate change impacts. Nonetheless, the IPCC scientists warned that we could not get back the moderate weather patterns of the past.
Ed Hawkins, a lead author of the IPCC and a climate scientist at the University of Reading, commented in the same warning tone: "We are already experiencing climate change, including more frequent and extreme weather events, and for many of these impacts, there is no going back."
