Time To Wake Up: The Ocean Heat Bomb
As-prepared for delivery
It is hard to overstate the importance of the Earth’s oceans, as a storehouse of our food, a regulator of our climate, a highway for our travel and trade, and a source of wonder and recreation. According to the Organization for Economic Cooperation and Development, oceans contributed $1.5 trillion to the global economy in 2010. But climate change is putting this all at risk.
I’ve spoken frequently here on the floor about the threat climate change poses to our oceans, and of the warning signals blaring around the world. One of the most overlooked of those signs is the enormous amount of heat accumulating in the oceans.
As CBS News reported last week, “recent revelations have been particularly alarming” and “deserv[ing] of a big neon sign on Broadway.” My humble floor speeches may not be a neon sign on Broadway, but I hope they help shine a light on the plight of our oceans, which ultimately is our plight.
We know that more than 90 percent of the excess heat trapped by our greenhouse gas emissions has been absorbed by the oceans. No dispute, even by the Trump Administration.
The federal government’s 2017 Climate Science Special Report, a multiagency report by experts from NOAA, NASA, and the Department of Energy, labeled as “the United States’ most definitive statement on climate change science” by the New York Times, found that the oceans absorbed more than 9 zettajoules of heat energy per year, or 9 billion trillion joules, from 1998 to 2015. That’s more than 12 times the total energy humans use globally each year.
To better understand just how much energy that is, visualize the power of a detonated Hiroshima-style atomic bomb, its classic mushroom cloud erupting into the sky. Imagine all of that energy captured as heat. Now imagine four Hiroshima-sized atomic bombs exploded every second. That’s the excess heat going in to our oceans. More than four atomic bombs-worth of excess heat energy is being absorbed by the oceans every second, of every day, of every year. That is a lot of heat energy, and adding it to the oceans has consequences.
The most direct result of all that energy being pumped into the seas is increased water temperatures. Global average ocean surface temperature is up around 0.8 degrees Celsius, or 1.5 degrees Fahrenheit, since pre-industrial times; enough to throw off the delicate balance of ocean conditions marine creatures rely on to survive.
Within that increase are extreme ocean temperature spikes around the world. These marine heatwaves, as they’re called, were first identified and characterized in 2011, but they have already caused permanent damage in our oceans.
The Great Barrier Reef is the largest coral reef in the world, stretching for 1,400 miles off northeastern Australia, and it is one of the seven natural wonders of the world. It’s made up of corals that can become heat-stressed and evict the tiny algae that support them and give corals their bright colors. Without the algae, the corals appear white, so these events are called “coral bleaching.”
In the summer of 2016, the Great Barrier Reef was hit by the most severe marine heatwave on record. It caused the longest and worst mass coral bleaching event in history. Then another heatwave and bleaching occurred in 2017. These unprecedented back-to-back bleaching events killed half of all corals in the Great Barrier Reef.
The prognosis for the rest of the world’s coral reefs is grim. The United Nations’ International Panel on Climate Change released a report last month finding that coral reefs will all but disappear from Earth if we warm by 2 degrees Celsius. Without any changes to our fossil fuel consumption, we are on track to blow by 2 degrees and hit 3 degrees Celsius of global warming by 2100.
Warming oceans are wreaking havoc on the world’s fisheries. Fish feed the world and power coastal economies. The World Health Organization says that fish are the main source of protein for around a billion people worldwide. The United Nations Food and Agriculture Organization estimates that 60 million people are employed in fisheries and aquaculture.
Across the globe and here at home, we’re seeing dangerous shifts affecting the fishing industry. Rhode Island once had a booming lobster fishery. But the lobster population is shifting north as our waters warm, leaving Rhode Island lobster traps empty. The National Oceanic and Atmospheric Administration reports, “[t]he lobster industry in New York and southern New England has nearly collapsed.” Maine is temporarily benefiting from the northern movement of lobster, but the lobster will keep moving north, into Canada, as the oceans continue to warm.
Rhode Islanders and other New England fishermen are also looking worriedly at declining shellfish populations. Total landings for eastern oysters, northern quahogs, softshell clams, and northern bay scallops declined 85 percent between 1980 and 2010. The National Oceanic and Atmospheric Administration’s Northeast Fisheries Science Center identified warming ocean temperatures as the key driver for the decline.
The accumulating heat energy in our seas is also causing them to rise. As water warms, it expands. This thermal expansion is responsible for around a third of the rise we’ve seen in sea levels. The rest comes mostly from melting ice, again thanks to climate change. Global sea level has already risen over 8 inches in the past 100 years, and the rate of increase is accelerating.
Warming and expanding waters eat away at the large ice sheets in the Antarctic. As the edges melt away, the glaciers behind them melt more quickly, adding additional water to the ocean. The IPCC warns that as the world reaches warming levels of 1.5 to 2 degrees Celsius, ice sheet melt could trigger multiple meters of sea level rise. We’re already 1 degree Celsius above pre-industrial times, so there’s not much room for maneuver.
Warmer seas also supercharge storms. Hurricanes gain strength from heat energy in the oceans below them. Warmer oceans also evaporate more water to the atmosphere, generating more rainfall. Stronger and wetter storms then ride ashore on higher sea levels, pushing larger storm surges ahead of them into our coastal states.
We all remember the devastation Superstorm Sandy brought to the Mid-Atlantic and Southern New England in 2012. Here’s what Dr. Michael Mann, professor of atmospheric science and director of the Earth System Science Center at Pennsylvania State University, said about that storm:
Sea level rise adds to the storm surge of every single storm that makes landfall. In the case of Superstorm Sandy, in 2012, it added a foot to that 13-foot storm surge. One foot… meant 25 more square miles of coastal flooding. It meant several billion dollars worth of additional damage.
At one point during this year’s hurricane season, our tropics faced nine active tropical storms. The hallmarks of these warm ocean-fueled storms can be seen in powerful hurricanes that hit the United States in recent years: Hurricane Harvey in Houston, Hurricane Maria in Puerto Rico and the Virgin Islands, Super Typhoon Yutu in the Northern Mariana Islands, Hurricane Florence in the Carolinas, and Hurricane Michael in Florida.
No one storm can be blamed wholly on climate change, but scientists are increasingly able to link the increasingly dangerous level of storm damage to climate change.
We’ve had an eerie streak of record-setting storms in the past few years. Hurricane Harvey was the single greatest downpour in United States history, according to the United States Geological Survey, dumping over 50 inches of rain on Houston and over 30 trillion gallons of water over Texas, Louisiana, Tennessee, and Kentucky. For comparison, the Chesapeake Bay holds around 18 trillion gallons of water.
Harvey’s deluge was fueled by record warm temperatures in the Gulf of Mexico. Scientists from the University of California-Berkeley found that Hurricane Harvey was over three times more likely to have occurred due to climate change, and that its rainfall was increased by around 38 percent.
Hurricane Florence intensified over water 1 to 2 degrees Celsius above average, and dumped record rainfall and flooding on the Carolinas in September. Preliminary analysis suggests its rainfall was more than 50 percent higher due to climate change.
When Hurricane Michael hit Florida just last month, it passed over water 2 to 3 degrees Celsius warmer than average. As it passed over these waters, Michael's winds increased by 80 miles per hour in 48 hours, a phenomenon scientists refer to as “rapid intensification.” It became the strongest storm ever to make an October landfall in the United States.
The direct link between sea temperature and hurricane intensification is well established: each degree Celsius of ocean warming causes a 7 percent increase in maximum wind speed. A storm’s destructive potential increases by three times the wind speed increase.
To quote Professor Mann again:
A 7 percent increase in wind speed is a 21 percent increase in the destructive potential of the storm. That's with 1 degree Celsius ocean warming. With Hurricane Michael, those temperatures were 2 to 3 degrees Celsius above pre-industrial temperatures. If you do the math, that means it was probably twice as destructive as it would have been in the absence of human-caused warming.
The result of the destructive power of Hurricane Michael was the almost complete demolition of the town of Mexico Beach, Florida. Michael hit with 155 mile per hour winds and a storm surge of around 9 feet, completely demolishing 70 percent of homes and severely damaging many more.
The degree of damage and the imposing costs of rebuilding mean that many Floridians simply will leave. A falloff of coastal property values will spread as people see more events like the destruction of Mexico Beach. Insurance companies, banks, and property investors are already showing signs of anxiety in coastal communities.
Freddie Mac has described the effect of this property value crash on America’s coastal regions as follows: “The economic losses and social disruption may happen gradually, but they are likely to be greater in total than those experienced in the housing crisis and Great Recession.” Moody’s now rates coastal municipalities’ bonds for this risk.
Despite these warnings, Republican heads in Congress and in the White House seem determined to remain buried in the sand. How many more storms need to hit us before we’re willing to take meaningful action? Americans who live and work along our shores are suffering most from our delay. They’re entitled to a voice, not just the fossil fuel industry.
We must protect our coasts for when the next storms batter their way ashore. And we must take responsibility for the changes we are causing in the world’s oceans.
Mr. President, our oceans are warning us loud and clear: it’s time to wake up.
I yield the floor.
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