Natural Environment 7.6: Climate Change

A great body of science supports the contention that the world’s consumption of fossil fuels has resulted in increased dispersion of greenhouse gases, altering the planet’s atmosphere to the point of global warming and resultant rapid acceleration of sea level rise. In turn, these environmental changes may flood buildings and infrastructure, shift locations of habitats, alter growing seasons for crops, introduce new pests and invasive species, increase extreme weather events (droughts, flooding, and storms), and create more health stress from extreme heat and poorer air quality. Though there is some uncertainty about the extent and timing of the changes communities can expect, current evidence and projections suggest that impacts to the Vineyard are potentially of such magnitude or importance that it is only prudent to anticipate and plan for such contingencies.

Much of the focus of climate change impacts has been on sea level rise. According to the Intergovernmental Panel on Climate Change, by the end of the 21^st Century we may expect worldwide (eustatic) sea level rise of about 7-15 inches (from a temperature increase of 3.2 degrees F) to 10-23 inches (from a temperature increase of 7.2 degrees F). Recent projections are even greater.

The potential sea rise is much greater for Martha’s Vineyard. The Cape and Islands are among many areas around the world under which the earth continues to gradually subside in response to the end of the Ice Age. This local subsidence has added to the submergence felt world-wide, so that in the last 100 years, sea level has risen in our area between 10.2 inches (at Woods Hole) and 11.9 inches (at Nantucket), compared to the 6.7 inch worldwide rise in sea level.  It is reasonable to assume that local sea level rise may be significantly higher than worldwide projections, meaning that significant public infrastructure as well as private properties on the Vineyard are at risk, and will be inundated at some point.

Section 4 (Energy & Waste) outlines measures to reduce the Vineyard’s contribution to greenhouse gases by adopting practices that do not generate as much harmful emissions, such as using energy more efficiently and using clean, renewable energy sources. The open space protection measures in this section will help conserve vegetation that locks up carbon, and filters and cools the air.

However much the Vineyard demonstrates responsible action, it is now clear that we must prepare to adapt to the inevitable impacts of climate change.

Objective N10: Prepare for climate change. 

We need to assess the vulnerability of the Vineyard to the diverse impacts related to climate change and plan accordingly to best conserve human and natural resources.

Some of the measures outlined elsewhere in the Island Plan will help the community deal with the impacts of climate change. Increased heat stress to coastal ponds will probably promote growth of various undesirable plants and animals, further deteriorating water quality, and making decreasing nitrogen input to groundwater even more important. The preservation of large, Minimum Viable Landscapes of native habitat will allow communities and species and species of plants and animals to shift in response to climate stress on community composition and locations.

·  Strategy N10-1: Identify lands/infrastructure most at risk to sea level rise. A Climate Change Plan should be prepared for the Vineyard that uses computer modeling to identify lands at greatest risk from sea-level rise, based on considerations such as previous shoreline change, topography, and a likely range of sea-level change. It should identify areas likely to become underwater, wetlands, or subject to storm surges. This Plan should identify the measures that the Vineyard should use to adapt to and/or mitigate the impacts of climate change, such as those mentioned in the other strategies below.

·  Strategy N10-2: Limit construction in areas at greatest risk and adopt measures to limit impacts. Construction – or reconstruction after storm damage -- of buildings or infrastructure should be prohibited in the most highly susceptible areas, including areas which would prevent wetlands from migrating inland so they can continue to play their essential ecological/environmental roles. This would include a policy to prevent shoreline “hardening” that attempt to hold back the change and prevent beaches from rebuilding their own storm defenses such as dune systems. Buildings that are damaged in storm surges may contribute significant impacts as toxins, debris and septage enters ponds and bays, and affect water quality, shellfish, and public use of these resources.  Building codes should be updated to ensure higher elevations and distance from shorelines as protection from storms and flooding. 

·  Strategy N10-3: Preserve lands that are susceptible to climate change impacts as open space. Acquire lands in areas identified as highly susceptible – especially if they are ecologically important or serve some other open space purpose. Federal pre-disaster mitigation funds may be used acquire land to “un-develop” properties that cannot be mitigated

·  Strategy N10-4: Carry out pre-disaster mitigation to reduce impacts from storms and flooding.  The MVC and Island Towns recently prepared a Pre-Disaster Mitigation to help identify facilities most at risk from natural disasters, and to identify what measures could be taken to minimize impacts in case of an event. This plan should be updated to incorporate projections related to climate change. For example, more aggressive fire-wise strategies such as removal of fuels and their replacement with native vegetation would help deal with the anticipated increased summer fire hazard.