The alarming rate at which our oceans are warming is not a new topic for the scientific community. However, recent research suggests that the ocean is heating at a much faster pace than previously estimated. This development brings a new challenge for global climate goals, as it means more heat is being retained within Earth’s climate system annually, instead of escaping into space. It indicates that global warming is far more advanced than we presumed.
Implications of Increased Ocean Heating
The study found that since the 1990s, global oceans might be absorbing up to 60% more heat compared to former estimates. Old estimates from the U.N. Intergovernmental Panel on Climate Change (IPCC) recorded that the oceans were taking in around 8 zetajoules of energy each year (1 Zetajoules equals 1021 joules). The new findings put this figure around 13 zetajoules.
This data implies Earth, as a whole, may be more sensitive to climate change than believed before. The planet could potentially respond more severely to future greenhouse gas emissions.
| Energy Consumption | Amount |
|---|---|
| Yearly global energy consumption | half a zetajoule |
| Ocean energy absorption (old estimate) | 8 zetajoules |
| Ocean energy absorption (new estimate) | 13 zetajoules |
The International Energy Agency states that total energy consumption worldwide is around half a zetajoule per annum. The recently discovered increase in ocean heating could have grave implications on global efforts to achieve climate targets.
The Paris Agreement and Deteriorating Climate Goals
The nations under the Paris Agreement are tirelessly working to keep global temperatures within 2 degrees Celsius of their pre-industrial levels. A recent report by the IPCC on the 1.5 C threshold concluded that meeting the target would necessitate an “unprecedented” effort from world leaders, requiring net-zero carbon emissions by 2050.
However, if governments aim to prevent temperatures from rising above 2 degrees Celsius, carbon dioxide emissions must be reduced by 25% compared to previous expectations.
Comparing Past and Recent Research
This most recent study is not the first to denote that the IPCC’s earlier estimates might be too low. Other research conducted over the past few years also suggests faster ocean warming. However, the exact rate varies from study to study.
New Approaches to Collecting Ocean Data
Measuring ocean temperatures consistently involved using thermometers throughout the globe. However, before 2007, scientists relied heavily on measurements taken by passing ships, resulting in limited data. This changed in 2007 when an international consortium launched a program called Argo that created an international network for measuring ocean temperature and salt content.
The new research bypassed the issue of collecting direct ocean data by depending instead on atmospheric oxygen and carbon dioxide measurements dating back to 1991. Oceans absorb over 90% of the excess energy trapped within the world’s atmosphere. Thus, any change in atmospheric oxygen and carbon dioxide levels helps estimate the ocean’s heat content changes over the last few decades.
Limitations of New Techniques
This novel approach’s effectiveness remains uncertain and needs further scrutiny. Additionally, while it works well over long periods, it provides no insight into yearly changes. Nevertheless, this method marks a significant improvement in our attempts to understand and document the worrying trend of rapid ocean warming.