Intergovernmental Panel on Climate Change in its latest report ( released on 7 October 2018) said , “ IT IS possible to keep the increase in global average temperatures to within 1.5 degrees Celsius of pre-industrial times (Period of 1850- 1900/Second industrial Revolution). But for that, the world would need to bring down its greenhouse gas to about half of its 2010 levels by 2030, and to net zero by about 2050”.

In its earlier reports, which have formed the basis of global action, the IPCC has said that climate change could have “irreversible” and “catastrophic” impacts if the global average temperatures were allowed to rise beyond 2 degrees Celsius. The latest report, released in Seoul Saturday at the end of a week-long meeting, was requested by various countries in 2015 to explore the possibilities of keeping the temperature rise within 1.5 degrees Celsius. This was the key demand made by a number of smaller and poorer countries, especially the small island states, which face the maximum risks from the impact of climate change.

As of now, the world is striving to prevent the temperature rise beyond 2 degrees Celsius, in accordance with the stated objective of the Paris Agreement of 2015. To meet that target, the aim is to reduce greenhouse gases by only 20 per cent, from 2010 levels, by the year 2030 and achieve a net-zero emission level by the year 2075.

Net-zero is achieved when the total emissions is balanced by the amount of absorption of carbon dioxide through natural sinks like forests, or removal of carbon dioxide from the atmosphere through technological interventions.

If there is one message from the latest report of the Intergovernmental Panel on Climate Change (IPCC), it’s this: Checking global warming will require major changes in the Paris Climate Pact’s targets. The 2015 agreement, which has become the cornerstone of climate change mitigation efforts worldwide, proposed to keep the increase in global average temperature to below 2°C above pre-industrial levels. But the report that was released on Sunday has found this threshold to be inadequate. A more than 1.5°C warming will be precarious, and a 2°C rise would be catastrophic, the report warns. The world, already 1°C hotter than what it was 150 years ago, could witness greater frequency of droughts and floods, more intense tropical cyclones and increased ocean acidification and salinity if the planet heats by a further 0.5°C. That could happen anytime between 2030 and 2050, the report cautions. This means that current mitigation efforts — calibrated to stave off calamitous events by 2075 — will require drastic up-scaling.

What is worrying is that the world is not even on course to meet the comparatively conservative demands of a 2°C-rise-in-temperature scenario. In fact, one of the criticisms of the Paris Accord-mandated Nationally Determined Contributions (NDCs) is that they are insufficient to meet these demands.

However, IPCC has suggested 4 pathways through which keep increase in global average temperature below 1.5℃ is possible. In each of the pathways, the global average temperature is projected to overshoot the 1.5 degrees Celsius target by some amount before returning to that level before the end of this century. Each of these pathways is also dependent on some amount of Carbon Dioxide Removal (CDR), a reference to physical removal of the stock of carbon dioxide from the atmosphere to reduce its concentrations. Technologies for CDR are still undeveloped and untested. “ In simple words, in each of these pathways global average temperature may overshoot and these pathways is also dependent on some amount of CDR for which technologies are still undeveloped and untested.” Varying amounts between 100 to 1000 gigatons (billion tonnes) of carbon dioxide would need to be removed from the atmosphere in these four pathways, the report says. The world currently emits about 47 billion tonnes of carbon dioxide every year. “CDR would be used to compensate for residual emissions and, in most cases, achieve net negative emissions to return global warming to 1.5 degrees Celsius following a peak,” the report notes. The IPCC report says each of these pathways will require “rapid and far-reaching transitions in energy, land, urban and infrastructure (including transport and buildings), and industrial systems”.

The report also lists several specific advantages of keeping the global temperature rise within 1.5 degrees celsius from pre-industrial levels. Some examples are :

• At 2 degree, no ice in the Arctic Ocean in summer could be a once-in-a-decade phenomenon. At 1.5 degree the chance is a rarer once-a-century.
• At 2 degree, virtually all coral reefs (>99%) would be lost; at 1.5˚ the decline would be a little less at 70-90%.
• A 2 degree increase would mean extreme hot days in the mid-latitudes - India will be hotter by 4 degree; that comes down to 3 degree if the rise is at 1.5 degree. Cities will become heat islands.
• Limiting global warming to 1.5°C could prevent around 3.3 million cases of dengue every year in Latin America and the Caribbean alone.
• An additional 150 million people could be at risk from malaria if the temperature was allowed to increase beyond 2°C.
• The world could have 25 million fewer undernourished people by the end of the century, if the 1.5°C goal was achieved.
• About 350 million additional people could be exposed to deadly heat waves if the warming increased to 2°C as compared to 1.5°C.
• 1.5°C could prevent 153 million premature deaths due to air pollution by 2100, as compared to the 2°C scenario.
• * More than 90% of the world’s population could see the economic damage as a result of climate change being reduced in the 1.5°C scenario, Overall, the world could be 3% wealthier by 2100 in a 1.5°C scenario compared to a 2°C scenario.
• A 1.5°C strategy could create double the number of jobs in the energy sector by 2050.
• Also, compared to the 1.5°C scenario, extreme weather events such as heavy rainfall and heat waves are likely to become more severe and frequent, and freshwater supply could fall sharply, in a 2°C world.

Summary:

IPCC - keep increase in global average temperature below 1.5℃ instead of 2℃ threshold (according to paris accord) above pre-industrial levels by end of this century. A more than 1.5°C warming will be precarious, and a 2°C rise would be catastrophic.

What is worrying is that countries’ current INDC goals are even inadequate to attain 2℃ threshold , how would they attain 1.5℃ threshold for which technologies are still undeveloped and untested ?

It's time to search an alternative planet for life ?  Asgardia may be future of life.