In the heart of the Hudson Valley courses a beautiful vulnerability. Named by various Native American tribes “the water that flows two ways,” the Hudson River is an estuary, created by fresh water flowing down from the Adirondacks and water being drawn up by the tides from the Atlantic Ocean. In this mix an extremely delicate intertidal zone is formed. There exists the rise and fall of the tide in a fresh water environment, which creates a unique set of ecological conditions. With predicted changes in tidal levels, temperature and climatic conditions, as is expected with global warming, there are many who anticipate changes in those river environments.
Back in the 1990s, Doug Burns, a scientist with the US Geological Survey, began to wonder about climate and its affects on local ecology. In a study published last year in the Journal of Hydrology, Burns and his colleagues found that the climate has warmed by just over a degree Celsius since the 1950s. Their highest elevation site, Slide Mountain (4,180 feet), showed the most warming of any climate station in the Catskills. So the snowpack, which is where much of the runoff in spring comes from, is affected. In fact, peak snowmelt is now five days earlier than in the past. If that warming trend persists, Burns anticipates a long-term water resource concern. The premature snowmelt already causes reservoirs to be at greater capacity in the beginning of winter and to fill earlier in the spring. Full reservoirs cause flooding as excessive precipitation overflows. Then, because the precipitation was not caught and stored, there is less in the reservoir later in the season.
Paul Huth has been recording weather at Mohonk Preserve’s Daniel Smiley Research Center for the past 34 years. Originally established in 1896 by the US Weather Bureau (now the National Weather Service), the center is beginning to work with the Lamont-Doherty Earth Observatory at Columbia University to examine 113 years of data and determine trends. Huth, the center’s director of research, said they have a rough handle on what they expect to find. Since 1896 there has been a 2.2 degree increase in overall temperature, and with their observations of seasonal changes in plants and animals—such as flowering, fruiting, migration, and singing—they have noticed changes correlating to climate. They observed that six formerly migratory bird species, including the robin, the song sparrow, and the turkey vulture, are now over-wintering in the region. In the last 25 years, they noticed the black vulture, a bird never previously seen in this region, staying in flocks in New Paltz. Huth also mentioned Bloodroot, a spring ephemeral plant, which is blooming 14 days earlier than it did in the 1930s.
In interviews, Burns and others cited reports by the Union of Concerned Scientists, noting that both national and international scientists are reiterating the fact that boosts to temperature and precipitation are accelerating faster in the past 30 years as compared to the past 100. More and more studies are connecting warmer climate with sea level rise, predicting an upsurge as glacial ice melts.
Because beaches emerge from their waters at narrow angles, storms that occur at a higher sea level will be harsher. “If the sea level goes up a foot,” Burns said, “it doesn’t mean that the storm surge will go inland a foot more. It’ll go inland many feet more.” Even in the case of the Hudson, with both beaches and steep embankments, this presents a problem because of the responsiveness of the river to storm surge. Storms are only expected to become more intense, so that much of our rainfall will be downpours as opposed to smaller events spread over a few weeks. Already, Burns and his team found that the Catskills are getting wetter as it warms. “What we found in our study is not what we actually thought we would find. The amount of precipitation has increased since the 1950s, quite a bit, on the order of 5½ inches.” With increasing development, intense storms mean amplified flooding as the water runs off impermeable surfaces. These paved roads, which don’t absorb rainwater or overflow from the river and tributaries challenge places like the Strand in Kingston. The Hudson River Maritime Museum, on the banks of the Rondout Creek, is already considering creating an off-site for their nonexhibited collections and other emergency plans.
Many attribute weather extremes all over the country to the increase in temperature, with Hurricane Katrina being the obvious example. But in recent spring seasons, storm discharges are becoming taxing locally. In 2005, it was reported that Ulster and Green counties received between two and just over five inches of rain over one weekend in April. The Wallkill River and Esopus Creeks flooded, causing roadways and bridges to be shut down for days. Waters from the Rondout Creek rose so quickly in Kerhonkson that 27 homes were inundated and Federal Emergency Management Agency had to offer aid. In 2007, Ellenville reported receiving just about 5.6 inches, while Saugerties received 6.77 in the span of one day. Many townships declared states of emergency and schools in the Kingston, Onteora, Rhinebeck, and Pine Plains districts closed. The Northeast Climate Impact Assessment defines the 100-year floodplain as “the maximum flood elevation likely to be equaled or exceeded on average once every century in a given location. In any one year, there’s a one percent probability that a 100-year flood will occur.” However, many towns in 100-year floodplains in the Valley are already experiencing unprecedented amounts of flooding, and the number of spring precipitation events being called “major storms” is becoming common, with consequences to the power grids, drinking water and people in need of emergency rescue.