Climate change is seldom out of the news. When people talk about climate change, they are actually referring to global warming, which is attributed to so-called man-made or “anthropogenic” greenhouse gas emissions. Most people appear to believe in, while a few reject, the reality of global land and sea warming. The opposing camps have raised their respective profiles via endorsements by politicians and celebrities. Global climate change protesters are in the ascendant, having publicised the environmental impacts of human activity through highly visible and vocal campaigning tactics.
High-profile climate change events seem to come in rapid succession. In London, we have been witnessing the non-violent civil disobedience campaign that was launched by Extinction Rebellion on October 31 2018. Swedish eco-warrior Greta Thunberg sailed from Plymouth in a yacht on August 14 2019 , her zero-carbon-footprint trans-Atlantic journey to New York being fuelled by solar panels and electricity from wind turbines. She arrived in Manhattan on August 29, in time for a UN climate conference. Even Prince Harry has entered the fray with various comments about ways to combat climate change.
There is, however, powerful opposition. President Donald Trump is one of those seemingly unconvinced about global warming. He consequently withdrew the US from the 2015 Paris Agreement on climate on June 2017, which committed signatories to voluntary reductions in carbon emissions to keep global temperature rises below 2 degrees Celsius. He cited unacceptable costs to the US economy and unfair competitive advantages to high-carbon-emitting countries like China and India.
The Earth is being constantly warmed by the absorption of short-wave solar radiation from the Sun and through the emission of long-wave infrared radiation by the Earth’s surface. This latter form of radiation is being retained by the blanketing effect of atmospheric greenhouse gases. The temperature of the Earth is partly the result of a balance between the input of the Sun’s energy and the loss of absorbed solar radiation back into the atmosphere.
The central thesis of global warming is a that a steady and sustained increase in atmospheric carbon dioxide concentration has resulted from the burning of fossil fuels (coal, natural gas and oil) and from changes in land use, such as extensive deforestation. Methane and nitrous oxide, also greenhouse gases, are being overproduced by intensive animal agriculture on farms and by landfill sites. These human activities and their effect on global warming form the basis for a global scientific consensus, as demonstrated by the 2018 Intergovernmental Panel on Climate Change (IPCC) Report. There, however, remains a small minority of climate scientists who disagree with the conclusions of the report.
The predicted effects of global warming are catastrophic and even apocalyptic. These include rising sea levels and the risk of flooding, caused by thermal expansion of the warming oceans and by the melting of both land ice (Greenland and Western Antarctic ice sheets; Arctic permafrost; glaciers) and sea ice; reversal of the Gulf Stream; and an increased likelihood of extreme weather events, including heat waves, summer droughts, more intense tropical cyclones, forest fires, flash floods and land slides.
Scientists who deny the reality of global warming point to the natural and cyclical temperature variability on Earth, urban heat island effects which cannot be explained by greenhouse gas emission, the capacity of ecosystems to adapt to climate change, and claim that rising carbon dioxide concentrations cannot be expected to cause such dramatic changes in climate in isolation. In addition, some dissenting scientists claim that a “consensus” is not the same as scientific truth and await a paradigm shift as far as global warming is concerned. For those who believe in conspiracy theories, “climate change deniers” are busy fighting the Goliath that is the “scientific establishment.”
Theories of global warming are also opposed by many with a major financial stake in carbon-emitting activities and industries. Naturally, conflicts of interest may result where scientists have links with, and are funded by, the fossil fuel industry.
The threat of global warming has led to several international initiatives to identify and tackle the underlying issues. The Montreal Protocol on Substances that Deplete the Ozone Layer was signed in September 1987 and led to the phasing out of chlorofluorocarbon (CFC) manufacture. The Intergovernmental Panel on Climate Change (IPCC) was established by the World Meteorological Organisation and the UN Environment Program in November 1988. The UN Framework Convention on Climate Change (UNFCCC) was signed at the Rio Earth Summit in June 1992 The Kyoto Protocol of December 1997 was sponsored by the UNFCCC and was the first international agreement to tackle global warming by setting targets for greenhouse gas emissions, and came in force by 2005. This international consensus is being supported by many activist organisations, such as Friends of the Earth and Greenpeace.
Global warming has political and economic impacts over and above its effects on the environment. It seems beneficial to all forms of life on Earth that the contribution of carbon emissions and controlling their sources is being given serious consideration and that support for renewable energy is gaining in momentum.
Ashis Banerjee (Earth dweller).