 "global warming, climate change, earth temperature")
The conclusion of the 28th Conference of the Parties (COP28) last week has reignited discussions about the crucial climate targets of limiting global warming to 1.5 degrees Celsius above pre-industrial levels. But what does this figure really mean, and how much has the Earth already warmed?
Origin of the 1.5 degrees Celsius target
The 1.5 degrees Celsius target originated from the Paris Agreement, an international treaty adopted by 195 countries in 2015 to tackle climate change. This target was set based on scientific evidence suggesting that limiting global warming to this level would significantly reduce the impacts of climate change. The Paris Agreement aims to limit global warming to "well below" 2 degrees Celsius by the end of the century and pursue efforts to keep warming within the safer limit of 1.5 degrees Celsius above pre-industrial levels.
Is it the right target?
The choice of 1.5 degrees Celsius and 2 degrees Celsius as targets is a matter of scientific debate and policy decision. While these targets are ambitious, they are considered necessary by experts. D Raghunandan of the Delhi Science Forum said, "Staying below 1.5 degrees Celsius is seen as crucial for avoiding the worst impacts of climate change, including significant loss of biodiversity, more severe extreme weather events, and greater risk to human health and food security. However, this target is not a perfect target, considering that various regions experience warming at different rates. For example, the Arctic is warming at double the average global rate."
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According to the Intergovernmental Panel on Climate Change (IPCC), burning fossil fuels causes more than 75 per cent of anthropogenic greenhouse gas emissions and more than 90 per cent of carbon dioxide emissions from human activities. Achieving the 1.5 degree Celsius target requires rapid and unprecedented changes to reduce emissions by 43 per cent by 2030, it said. IPCC has warned that global carbon dioxide emissions need to reach net zero around 2050 to stay within the 1.5 degree Celsius limit. According to the United Nations Environment Programme's 'Emissions Gap Report 2023: Broken Record –Temperatures hit new highs, yet world fails to cut emissions (again)', released in November, annual emissions in 2030 were expected to be at least 24 billion tonnes of CO2 equivalent higher than where it should be to align with the 1.5 degree Celsius goal.
Measuring global warming and how much has the Earth already warmed?
According to the United Nations Framework Convention on Climate Change (UNFCCC), global warming is measured by calculating the average temperature of the Earth's surface and comparing it to pre-industrial levels. This involves an intricate network of weather stations, ocean buoys, and satellites collecting data over time. Climate scientists use this data to create models that estimate global temperature changes. While the baseline for pre-industrial measures is not defined in the Paris Agreement, the United Nations IPCC uses a baseline of 1850-1900 for this target as it is the earliest period with reliable, near-global measurements.
The year 2023 is set to become the hottest on record. Emissions Gap Report 2023 shows that this year, for the first time, the world saw as many as 86 days where the mercury soared beyond the 1.5 degrees Celsius threshold. The data from the European Union's Copernicus Climate Change Service shows that 2023 has now had six record-breaking months and two record-breaking seasons, and the global average temperature for the year so far has been 1.46 degrees Celsius. The month of November, according to the EU agency, recorded extraordinary temperatures, including two formidable days that were warmer than 2 degrees Celsius above the pre-industrial era. This, according to the World Meteorological Organization (WMO), will worsen further in 2024 because of increased heat as a result of spiking ocean temperatures and the 'El Nino' effect, raising the possibility of another record-breaking year of temperature rise.
However, there's a significant distinction between global temperatures on individual days and the long-term average. The latter is the focus during discussions like the COP28. Examining individual days or focusing on specific world regions reveals that the 1.5 degree Celsius threshold is being exceeded locally and regionally.
COP28 renewed commitment to 1.5 degree Celsius goal
Leaders at COP28 agreed to cut fossil fuel emissions to keep the 1.5 degrees Celsius target alive. Along with the much-awaited operationalisation of the loss and damages fund for climate actions, the first global stocktake (GST) text has been adopted that urges countries to triple their global renewable energy capacity, phase out unabated coal power, and transition away from fossil fuels in their energy systems, in order to curb emissions.
Now, all eyes are on COP29, which is set to take place in Baku, Azerbaijan, next year.
