John Swigert: “OK, Houston, we’ve had a problem here.”
Houston: “This is Houston. Say again please.”
Jim Lovell: “Houston, we’ve had a problem.”
That famous and chilling conversation by the crew of Apollo 13 aboard their ill-fated spacecraft could very well describe the Earth’s condition at this time.
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Today, we are seeing rising sea levels from global warming that can have devastating consequences. The rising seas combined with waves generated by high winds, storm surges, storm runoff and tides, put billions of us who live along populated coastlines in harm’s way.
Satellites have been measuring the threat. Years ago, NASA launched two satellites from Vandenberg Air Force Base — Jason 1 in 2001 and Jason 2 in 2008. This year, the NOAA and the European Organisation for the Exploitation of Meteorological Satellites are scheduled to send Jason 3 into space from Vandenberg with help from NASA.
These satellites measure sea levels over most of Earth using an extremely precise radar altimeter.
The altimeter transmits radio waves from the satellite to the ocean’s surface and measures the time it takes for the radio waves to bounce back. This technique has proved to be particularly precise and accurate. In fact, Jason 3 has a goal to measure sea-level variations of 1 inch, or 2.5 centimeters.
“These satellites give us a global view of our changing oceans with such exquisite accuracy that even the yearly rise and fall of global sea level is visible, caused by the transfer of water to and from the continents in the form of rain and river runoff,” said climate scientist Josh Willis of NASA’s Jet Propulsion Laboratory in Pasadena. Willis has been an authority on sea-level changes for many years.
Sea-level change is the best way to measure global warming.
The average rise in the sea level has been fairly steady over the past few decades at about 3.2 millimeters per year. However, from late 2010 into early 2011, the global sea level fell by about half a centimeter. Since that anomaly, the relentless rise in sea level has resumed.
So what caused sea levels to briefly stop rising in 2010 and 2011?
Willis says you can blame it on the cycle of El Niño and La Niña in the Pacific Ocean. Out over the ocean, sunlight and wind evaporate unfathomable amounts of seawater into nearly pure water vapor in the atmosphere. While most of it falls right back into the ocean as rain and snow, some falls over land.
A strong La Niña pattern developed in 2011. This sudden shift in the Pacific changed precipitation patterns globally, bringing unimaginable floods to places such as Australia, which ended one of the worst droughts in history.
That year, the Mississippi River reached levels never before seen by anyone alive. Severe floods also raged across the Amazon basin, the largest watershed in the world. By late 2011, all of that rain finally made its way back into the oceans, bringing the sea level back up again.
Another, but much more important factor that affects sea level is the absorption of heat by the oceans. When water warms, it expands. Over the past five months, seawater temperatures along our coastline have been at near-record levels, despite the fact that we’re not in an El Niño condition. Sea levels have risen several inches higher than those predicted in the tide tables.
This is because of the thermal expansion of the upper levels of the ocean. This, along with melting glaciers and ice sheets in both hemispheres, pushes sea levels higher over time. This makes sea-level variation a vital indicator of climate change.
You see, historical records indicate gradual changes in sea level over thousands of years, but since the end of the last ice age, we have not seen anything quite as dramatic as the past few decades of rising sea levels.
“Unfortunately, the ocean is doing pretty much what we would expect it to do in an increasingly warmer world. The sea level will continue to rise, and coastal floods as shown in your picture will, over time, become more commonplace,” Admiral David Titley told me.
He is the former oceanographer and navigator of the Navy. He is now a professor at Penn State and founding director of Penn State’s Center for Solutions to Weather and Climate Risk.
Regrettably, as we continue to dump about 5 million tons of carbon dioxide (CO2) into the atmosphere every hour from the burning of fossil fuels, the rise in sea level will continue.
“The increase in the rate at which the average global sea level is rising is just what is expected from climate models. Many low-lying areas, like Miami, are already feeling the impacts. It will only get worse unless we quickly control CO2 emissions,” astronomer Dr. Ray Weymann said.
In the United States, the generation of electricity is one of the largest contributors of CO2. However, in PG&E’s service territory, the generation of electricity utilizing nuclear, hydroelectric, solar, wind, geothermal and biomass has made our state one of the cleanest in the country. In fact, more than 50 percent of the electricity that PG&E delivers to its customers is carbon free. With each passing year, it’s expected to become cleaner.