As a scientist who spent a career studying the ocean, I am alarmed, but not surprised, by the new United Nations report on the implications of climate change for oceans and Earth’s ice masses. As humankind increases concentrations of carbon dioxide and other greenhouse gases in the atmosphere, the world is warming. The oceans are storing most of this heat, resulting in more intense hurricanes, reduced oxygen levels and death of coral reefs. Polar ice sheets are now melting, raising ocean levels. The consequences will be very severe if we don’t act quickly to limit warming.
What does this mean for our treasured arm of the ocean, the Chesapeake Bay? In particular, what are the implications for sea-level rise that increasingly threatens low-lying areas of Maryland, both rural and urban?
Over a 10-year period, I led panels of scientists in estimating sea-level rise likely to be experienced in Maryland for use in the state’s planning. So, I anxiously turned to the section of the U.N. report containing the new consensus sea-level rise forecasts. Do they differ from our last recommendations made just a year ago?
I was relieved to discover that the new forecasts align closely with our estimates for Maryland, with one important exception. If the world’s greenhouse gas emissions continue to increase through this century, the rise in sea-level in Maryland is projected to be nearly 1 foot higher than the 2 to 4 feet that we had thought was likely by the end of this century. That gap widens during the next century. The increase is due to new understanding of the melting of the polar ice sheets.
There is some good news in the U.N. report. If we are able to reduce carbon emissions to meet the goals of the Paris Agreement to keep the world’s average temperature increase to well below 2 degrees Celsius (3.6 degrees Fahrenheit), sea-level rise experienced in Maryland could remain under 3 feet well into the next century. If we don’t, the rise could be as much as 10 feet. According to another recent U.N. report, the world must eliminate its net carbon dioxide emissions by 2050 or shortly thereafter to stay well below 2 degrees. We cannot leave this to our grandchildren to tackle later because by then the meltdown of polar ice could not be slowed.
So, we should anticipate and prepare for a 3-foot rise in sea level that is probably unavoidable over the coming decades, but, most essentially, we must reduce carbon dioxide and other emissions as rapidly as possible. Of course, Maryland is responsible for only a small part of global emissions, but surely it has a disproportionate responsibility to lead as the most affluent and best educated state in the world’s most powerful country.
Indeed, our state is well-positioned to lead. Our governor and attorney general are currently in the courts fighting the Trump administration’s nihilistic actions to roll back limits to power plant emissions and auto mileage requirements. We are building on the accomplishments of the Regional Greenhouse Gas Initiative to use market forces to reduce power plant emissions in the northeastern states, exploring ways to reduce transportation emissions as well.
As a crucial way point, our Greenhouse Gas Reduction Act requires that Maryland achieve a 40% reduction in emissions by 2030. But this goal needs a plan of actions and means to implement them. The Hogan administration is nine months late in releasing a draft of the action plan and seems more focused on building highways and bridges. There are increasing obstacles and decreasing incentives for the rapid and profitable expansion of solar energy. Meanwhile, the congressman representing Maryland’s Eastern Shore works to block development of offshore wind power.
It is encouraging that a Towson University poll found that 69% of Marylanders understand that humans are causing climate change. We must now move from understanding to action. It’s time for bold but economically sensible measures that lead to net zero emissions over only 30 years.
Maryland and neighboring states committed 32 years ago to clean up the Chesapeake Bay. We badly missed two pollution-limit deadlines and we are virtually certain to miss the third in 2025. With just five years to go, homestretch plans range from patently inadequate (Pennsylvania) to highly implausible (Maryland). The Chesapeake experience shows that insincere deadlines, voluntarism and half-measures will not be sufficient.
We have only one chance to limit planetary warming sufficiently to avoid runaway melting of Antarctica and Greenland. This time there can be no time extensions.
Donald F. Boesch (firstname.lastname@example.org) retired as president of the University of Maryland Center for Environmental Science.