A recent study alarmingly reveals that global temperatures have not only surpassed the critical 1.5°C threshold set by the 2015 Paris climate agreement but are also on a trajectory to exceed 2°C within this decade.
Published in Nature Climate Change, the University of Western Australia’s Professor Malcolm McCulloch’s groundbreaking research utilised a unique method to analyse sea sponge skeletons, tracing back 300 years of ocean temperature records.
His approach has unveiled the fact that the pace of global warming is far more advanced than previously understood.
Researchers examined the chemical composition of long-lived sea sponges from the Eastern Caribbean, offering a new perspective on the historical progression of ocean warming.
This method underscores the limitations of traditional ocean warming measurements which rely primarily on sea-surface temperature records dating back only 180 years, potentially underestimating the extent of human-induced climate change.
Reacting to the study’s findings, Dr John Kleinsman, Director of the Nathaniel Centre for Bioethics, emphasised the urgent need for immediate action to reduce carbon emissions.
“It is unfortunately the case that we are not making as much progress in reducing emissions as we need to avoid even greater catastrophes than we are already experiencing” Kleinsman told CathNews.
He highlighted the necessity of overcoming apathy and denial, advocating for “long-term transformational changes that are both personal and collective.”
This call to action echoes the sentiments from the New Zealand Catholic bishops’ document Te Kahu o te Ora, urging a comprehensive response to the climate crisis.
Despite some climate scientists expressing scepticism about the study’s isolated approach, Kleinsman argues that the research further underscores the critical need to reduce global carbon emissions.
This sentiment is a stark reminder of the ongoing challenges in mitigating climate change impacts and the collective effort required to address this global issue effectively.
The study
In the depths of the Caribbean Sea, ancient sponges with hard skeletons have been silently documenting ocean temperatures for centuries.
Researchers including McCulloch and teams from Indiana State University and the University of Puerto Rico, analysed these sponges which absorb strontium and calcium in temperature-dependent ratios.
Their study reconstructed 300 years of ocean temperatures, integrating these with land-based records to assess global warming.
These deep-sea sponges, unaffected by short-term temperature fluctuations and reflective of global averages, confirmed the accuracy of historical temperature trends including a notable drop after the 1815 volcanic eruption in Indonesia.
The study claims that the method addresses inconsistencies in 19th-century ship-based temperature recordings. It further suggests that significant global warming began around 1860, earlier than the “pre-industrial” period defined by the IPCC, challenging current benchmarks for measuring global heating rates.
Sources
- The Conversation
- Supplied
- The Guardian