Greenhouse gas emissions in 2020 could be between 8 billion and 13 billion metric tons (14.33 billion tons) above what is needed to limit global warming to two degrees Celsius, a United Nations’ Environment Program (UNEP) report shows.
The World Bank warned this week that the world is likely to warm by 3-4 degrees by the end of the century and extreme weather will become the “new normal”, affecting every region in the world.
A National Research Council report, Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia (2011) states that we should expect “an estimated 0.5-1.0 meter (20-39 inches) of mean sea-level rise (SLR) by 2100, with some correlation studies predicting SLR up to 1.6 meters (63 inches) by 2100 for a warming scenario of 3.1°C (5.6°F).”
As they rise, the world’s seas are also gradually acidifying. This is because of the increasing amount of CO2 absorbed by oceans, which has equaled about a quarter of human produced CO2 emissions in recent years.
I see no evidence that the world is prepared to address this issue. U.N. scenarios indicate that cuts of 25 to 40 percent are needed to limit temperature rise. China accounts for 10 billion tons annually, and shows no sign of curtailing its emissions. The US did decrease its emissions by 2% last year, but still weighs in at almost 6 billion tons. Unless the world’s leaders are finally willing to address climate change in a meaningful way, a rise of at least 2 to 3 feet by the end of the century is a lock.For the moment I am ignoring other impacts such as the increased severity and frequency of storms and droughts, and the unceasing rise in temperatures. I am focused only on SLR and its impacts on coastal communities and ecologies. Even more limiting, I am focused on birds.
Not every species of bird will be equally impacted by climate change. Not every impact will be seen in the near future. But which birds at the most at risk in the immediate future (decades, not centuries). Who’s on first?
Even a foot of SLR inundates beaches, tidal flats, barrier islands, and coastal mangroves. There are places where these shoreline and near shore communities will simply migrate inland. But what about those places where this migration is blocked by development, mountains, and the like? Recent studies in the Caribbean have pointed to the need to “climate proof” coastal infrastructure such as buildings, resorts, airports, and roads. But climate proofing often entails hardening the shore with sea walls and rip rap, leading to a gradual loss of the beach and tidal flats.
The birds that inhabit those coastal habitats will be the first to feel the impacts of SLR. Therefore we need to identify which of these species are the most at risk, and develop strategies for insuring their continued survival.Let’s begin with species with low populations. An example of a low density coastal resident is the American oystercatcher. Birdlife considers this to be a species of Least Concern. Of course concern is relative, and as long as we ignore SLR I suppose that the bird is relatively safe. But obviously we can’t (or shouldn’t) discount SLR, and therefore I will argue that the oystercatcher deserves great concern.
Other coastal birds concentrate in a limited number of breeding colonies. For example, 90% of the world’s Heerman’s gulls nest on the island of Isla Rasa off Baja California in the Gulf of California. The magnificent frigatebird colony in Barbuda is the largest in the Caribbean. Frigatebirds lay one egg, and take over a year to become independent. Color-tagged frigatebirds from Barbuda have been reported from as far away as Florida. With SLR, such colonies are at risk, and therefore a large percentage of the world’s populations of these birds are at risk as well.Coastal birds may be limited by suitable breeding habitats as well. For example, the snowy plover is limited to the immediate shore in the Caribbean. Reddish egrets are likewise restricted to coastal sites. These birds, along with others such as the least tern, Wilson’s plover, and royal tern, are squeezed into a narrow fringe that borders the coasts. With SLR that fringe unravels.
The same is true for species that depend on the similar habitats in winter. Species such as the piping plover, black-bellied plover, red knot, and ruddy turnstone are coastal obligates. Most show strong winter site fidelity. Just precisely where are these birds to go when their winter beaches and tidal flats are inundated?Many shorebirds only pass through these Caribbean sites on their way to winter in South America (which will suffer SLR as well). Often these birds only use these sites during times of severe weather. But if these life savers are lost, precisely where are the birds to go? A white-rumped sandpiper may need to stop-over only once in its life, but for that critical moment these sites are irreplaceable.
Climate change demands a change in conservation approaches as well. We need an adaptive conservation, one that recalibrates and redirects as climate change is better understood and its impacts projected. Each year brings new information and more certainty, and our conservation needs to reflect these new data.Adaptive conservation first demands that we know the current condition. In the Caribbean we need to know which birds are at immediate risk, population sizes, habitat requirements, and geographical range. We need a more fine-grained approach to inventorying seabirds and shorebirds.
Not only do we need to know where these species nest, but we also need to know details about the specific sites. For example, what could be more critical than elevation? Precisely how high is a seabird colony elevated above sea level? We need these data in fine increments, not the rough estimates available from current GIS sources. Without knowing elevations, how can we prioritize our conservation actions in the near future?
We then need to use this current condition analysis to project the impacts of SLR based on the most current climate change data. When the data change, our projections and conservation actions should change. Our conservation should adapt to current conditions, not ignore them.Adaptive conservation also requires that we develop approaches for mitigating the projected losses due to SLR. For example, breeding islands that are destined for flooding may be saved through the beneficial use of spoil to raise their elevations. Spillover zones may be created and managed for species diversity. SLR is inevitable, but there are ways that we can adapt to this “new normal” without a catastrophic loss of coastal birds.
Finally, we need to engage the public in this issue and our conservation efforts. For example, approximately 70% of the Caribbean population lives along a coast. The fate of our birds is the same fate of the people.
Climate change will demand changes in policy, planning, economic development, and agriculture. Adaptive conservation requires that we, as people, adapt and shape our lives to better fit this new norm. For example, coastal resort development, never wise, becomes reckless in the light of climate change. The cruise industry, never light on the land or water, is indefensible given the carbon belched into the atmosphere by each ship.
For more information about adaptive conservation, this report from the Environmental Law Institute is an excellent beginning.
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