Topic: General Studies 2,3:
- Government policies and interventions for development in various sectors
- Conservation, environmental pollution and degradation
Flattening the climate curve
Two interrelated curves began their upward trend two centuries ago with the advent of the industrial age.
- The first curve was the atmospheric concentration of carbon dioxide (or, more generally, all greenhouse gases, GHGs)
- The second was the average global temperature curve.
Brief history of CO2 Curve
- The CO2 curve began its upward march about 18,000 years ago when it was a little under 200 parts per million (ppm) and earth was much colder.
- By the time it reached 270 ppm about 11,500 years ago, the warmer conditions accompanying this curve made it possible for the emergence of agriculture.
- Over the past million years, CO2 levels never exceeded 280-300 ppm. They always went back to 200 ppm before rising again in a cyclical fashion
- From mid-19th century, CO2 began to rise again as humans burnt coal & oil and erased forests to expand agriculture and settlements.
- From a mere 0.2 billion tonnes of CO2 emissions in 1850, annual emissions increased to 36 billion tonnes by 2018.
- However, one-half of all CO2 emissions have been sanitised from the atmosphere, equally by growing vegetation on land and by absorption in the oceans
- Thus, the levels of CO2 in the atmosphere reached 407 ppm in 2018, a level last experienced by earth some three million years ago.
Brief history of global average temperature Curve
- From 1850 onwards, for over a century, the global temperature showed a slight warming trend. But there was nothing suggestive of anything serious
- From 1975 onwards, the temperature graph has shown a distinct, upward trend.
- By 2015, the globe had heated by a full degree Celsius relative to a hundred years previously.
- Under the current trends of emissions, the globe will heat up by 4˚C by the end of the century.
- Extremely hot days (days above 35˚C), which were only five days in 2010, would increase to 15 days by 2050 and to 42 days by 2100 on average across all districts if the emissions continue at same rate
Manifestation of these upward trend curves
- Globally there have been several extreme and frequent weather events such as hurricanes, heat waves, floods or droughts
- The 2003 European heat wave killed over 70,000 people.
- The years 2015-19 have globally been the warmest years on record.
- The Amazon fire of 2019 and the bush fires of 2019-20 in Australia were unprecedented in their scale and devastation.
- If global CO2 emissions continue to gallop at the present rate, then average summer temperatures would rise by 4˚C in most States of India.
Paris Climate Deal and its challenges
The Paris Agreement’s long-term temperature goal is to keep the increase in global average temperature to well below 2 °C above pre-industrial levels; and to pursue efforts to limit the increase to 1.5 °C. However, some of challenges to achieve this goal are
- Dangers of post-COVID period: The most common excuse is that the world cannot afford to curb GHG emissions for fear of slowing the economy
- Inadequate Spending: The wealthy nations are spending over $500 billion each year internally on projects aimed at reducing emissions.
- IPCC, however, estimates that a sustained annual investment of $2.4 trillion in more efficient energy systems is needed until 2035 in order to keep warming below the more ambitious 1.5˚C relative to pre-industrial levels
- Inadequate Aid to Developing Countries: At the UN Climate Conference in 2009, the richest nations had pledged to provide $100 billion in aid each year by 2020 to the poorer countries for climate change mitigation and adaptation. In 2017, only $71 billion had been provided towards this purpose
- Change is mindset: The spectre of dangerous climate change impacting human civilizations has not yet evoked a response comparable to that seen in COVID-19 outbreak
This is a make-or-break moment for the climate trajectory which has to be flattened within a few years if we are to avoid dangerous climate change.