Each year, unfathomable amounts of energy are added to the oceans. Scientists measure heat in joules; the amount of heat in the oceans is so large that we report it in zettajoules. What is a zettajoule? It is 1,000,000,000,000,000,000,000 joules. The amount of heat we are putting into the oceans is equivalent to about five Hiroshima atom bombs of energy every second.
I am part of the team of researchers that published a paper on ocean warming that shows the total heat of Earth is increasing with global heating, as scientists have predicted for decades.
Each year, we take Earth’s temperature to try to determine what is happening to our climate. Each year the news is worse than the year before. There is hope, which I will discuss later. But first, let’s talk about the new study.
As humans emit heat-trapping gases into the atmosphere, it creates an energy imbalance. There is more heat coming in than going out. That means the Earth is out of balance, and temperatures are rising.
The vast majority of the excess energy – more than 90% – ends up in the oceans. Consequently, ocean temperatures are rising, and we can measure it.
Global warming is really ocean warming, and it has severe consequences. First, it makes ocean levels rise, because warming water expands. Scientists estimate that by the year 2100, oceans will be about 3ft higher than they were in the year 2000, displacing 150 million people around the world.
Warmer oceans also make our weather more extreme. They supercharge typhoons and hurricanes. They make rains more deadly and flooding more severe. The rising temperatures are also threatening sea life. We are experiencing major die-offs of coral reefs, which are incredibly important to ocean biodiversity. Rising ocean water is not just a problem for fish and sea life, it is a problem for everyone.
The leader of our team, Dr Lijing Cheng, developed an innovative way to measure ocean temperatures. We only get data where we place temperature sensors, and sophisticated mathematics are used to fill in the gaps and create a continuous picture of what is happening. His method of filling in the data gaps has been shown to be very accurate and scientists around the world have adopted the techniques.
Often when scientists report climate data, they try to show trends. It isn’t so important what the ocean temperatures were last year or what they will be this year. What really matters is the trend: are the oceans getting hotter or colder? Using the late 1990s as a reference, we see that years prior are colder and years after are warmer. In fact, we see that the oceans have warmed continuously since about 1990. This long-term trend is what climate breakdown looks like, and it is terrible news for the future of the planet.
All reasonable people know that the climate is warming and humans are the cause. Sometimes, I am asked for proof of warming, and there are many things I can point to: ice is melting, air temperatures are increasing, sea levels are rising, etc. But the best proof of warming is in the oceans. No one can dispute the data. The oceans are unequivocally warming.
So, what do we do about it? Well, we can begin to use energy more wisely. This will not only help with the climate crisis but save money as well. Secondly, we can maximise our energy from renewable sources such as wind, water, and solar. One of the things that gives me hope is that energy from solar and wind power is now cheaper than dirty coal. The benefits of solar and wind depend, of course, on how sunny or windy the conditions are, but with the drop in green energy prices, it no longer makes economic sense to build coal plants.
Another bit of hope is represented by the growing actions of our youth. Make no mistake, the Greta Thunbergs of the world will change things in ways that privileged middle-aged white men like me cannot. Their generation will inherit a dire situation, but they have the passion to act, and decades of unarguable evidence that they must.
So yes, 2019 set yet another dire record for Earth’s climate. But the fight continues to make the future more habitable for our children and their children.
