The long view
Repeated observations made over time give valuable clues to changes in the ocean due to global warming
PORTLAND, Maine - The front line of climate change research in New England is sandwiched between a camper and a Saturn on the high speed CAT ferry to Nova Scotia. As tourists upstairs watch movies, scientists inside a 20-foot mobile lab are in their 10th year of analyzing the salinity, temperature, and plant life of water the boat sucks in to cool equipment.
If the researchers can better understand some of the basic processes in this vast swath of sea, they might be able to figure out whether global warming is taking a toll here.
"We don't even know if coastal oceans emit more carbon dioxide" than they absorb, said William Balch, a senior research scientist for The Bigelow Laboratory for Ocean Sciences in West Boothbay Harbor, as he powered up six computers and set up instruments to measure nutrients, carbon, and other characteristics of the Gulf of Maine water.
Scientists need such information - and consistent monitoring of the environment - to understand how global climate change is affecting everything from squid to smog. Without the data, they could miss vital changes that will impact people's lives.
But there aren't enough of these observations, many scientists say, because funding is often directed toward research designed to make breakthrough discoveries or answer specific scientific questions.
The US government has been slow to replace aging earth-observing satellite equipment that gives critical information on the earth's climate systems, a 2007 National Research Council report noted. Several states that help fund the United States Geological Survey's 7,400 stream gauges, which measure water flow that can be a signal of climate change, say they will have to stop paying for dozens of the devices, because of cost-cutting.
And while government agencies are launching several initiatives to better monitor the environment, scientists say much more investment is needed - especially in geographical regions such as the Northeast that are already significantly warming.
"Without the measurements, you won't ever be able to look back to see what's changed with climate change," said Balch, a granddaddy of long-term climate change monitoring in the region.
Once, observing nature was a popular scientific pursuit. Naturalists in the 19th and 20th centuries catalogued the timing of plant buds, the date lake ice thawed in spring, and when species began migrating in the fall. Yet today, science is more directed at trying to understand how nature works.
"After 1950, there was a lot more interest in theoretical sciences, genetics, and models," said Robert Hirsch, a United States Geological Survey hydrologist. "A lot of it was figuring out how the environment would behave rather than figuring out how it was behaving."
Climate change has opened many scientists' eyes to the renewed need for long-term observations. After all, one of the first compelling pieces of evidence of man-made climate change came from basic measurements of atmospheric carbon dioxide levels that began at a Hawaiian observatory in 1958. And the only reason scientists know New England winters are warming up so fast is from long-term temperature records.
Despite that realization, the National Science Foundation - a critical funder of scientific research in the country - still gives the bulk of its money to scientists trying to answer specific scientific questions and even then, usually only in three- or five-year cycles. Officials there say their main goal has been to advance scientific knowledge and that does not always require long-term monitoring.
Now, Jim Collins, NSF's assistant director for biological sciences, said his agency is beginning more regularly to blend the two and ask, "What are those classes of questions that can only be resolved by a long-term data set?"
NSF is investing about $20 million this year to help develop The National Ecological Observatory Network, which will measure effects of climate change, land-use, and invasive species on ecology over time. Meanwhile, there are national and international efforts underway to install a wide array of monitoring devices in the world's oceans to understand how rising levels of carbon dioxide, for example, are making the seas more acidic.
Balch, in his cramped laboratory aboard The CAT, is looking for specific answers based on long-term data.
Balch, who is funded by NASA, measures carbon concentrations in water to follow how much is flowing off land from rivers and to track where it ends up. While he's taking measurements aboard The CAT, a NASA satellite more than 400 miles up snaps images of the Gulf to measure the amount of plant material, which needs carbon dioxide to grow. Balch then uses that information to determine how much carbon dioxide is being taken up across the region. He also compares his data set to the satellite's, to help develop better techniques for studying coastal seas.
Balch is beginning to see trends in his 10-year data set. There has been a decrease of marine plants in the eastern portion of the Gulf, but he's not sure what it means yet.
The Gulf's salinity is also decreasing - but it's not yet clear if that's from increased run-off from rivers or melting ice caps. He recently unearthed some Gulf of Maine measurements made more than 25 years ago that he can use to compare to today.
To get better measurements than he can riding on the CAT at 50 miles per hour, Balch and his assistants were recently trained to get some of the same measurements from an unmanned, underwater robotic glider. He is funded for two more years by NASA and hopes to get more money to continue the research for many more years.
"The value of these time series goes up exponentially with the amount of time you look at the system," Balch said. "It's all about keeping these long time series going." 