A study of sea sponges has found global warming had already cleared the 1.5°C threshold by 2020.
A research team, led by Professor Malcolm McCulloch from the University of Western Australia’s Ocean Graduate School and Oceans Institute, were able to uncover 300 years of ocean mixed-layer temperature records through sclerosponges. From this, they found industrial-era warming commenced in the mid-1860s, which works out around 80 years earlier than instrumental sea surface temperatures.
It also found global warming to be 1.7 °C above pre-industrial levels already by 2020, which is around 0.5°C higher than estimates from the Intergovernmental Panel on Climate Change (IPCC). The 2°C threshold is projected to be reached in the late 2020s now too, which is close to two decades earlier than had been originally anticipated. McCulloch tipped the global average temperature to soar past 2.5°C by 2050 going by current rates of emissions.
McCulloch continued: “The now much faster rates of land-based warming also identified in the study are of additional concern, with average land temperatures expected to be about 4 degrees above pre-industrial levels by 2050. Keeping global warming to no more than 2 degrees is now the major challenge, making it even more urgent to halve emissions by early 2030, and certainly no later than 2040.”
