By Kim Adelson – Five years ago, in 2014, the National Audubon Society released the results of its first research study on the effects of the climate crisis on birds. The grim news then was that roughly 50% of American birds – 314 of the 588 species examined – were at risk of losing at least half of either their summer or winter ranges by 2080 due to changes in temperature and precipitation. The authors noted that this was a conservative estimate of projected loss, since climate effects on factors such as habitat availability and sea level rise were not considered.
National Audubon scientists, in their updated report just released, find that 64% of studied North American species are at risk of extinction if global temperature increases by 3.0o C.
Fast forward, and it is now 2019. In the intervening half decade, Audubon Society scientists have refined their analyses by adding more data (they used more than 140 million data points drawn from 70 sources) and incorporating a wider range of climate effects (e.g. more frequent false springs, sea level rise, and increased forest fire devastation) into their models. They examined and compared the outcomes for birds under both a 1.5oC and 3.0oC increase in global mean annual temperature. These temperatures were selected because, according to the Intergovernmental Panel on Climate Change, if we take little or no action temperatures will rise by 1.5 o C by 2050 and by 3 o C by 2080.
What Audubon scientists determined in this more refined study is that 64%, or 389 of 604 studied North American species, are at risk of extinction if we allow global temperature to increase by 3.0oC. The birds that surround us — western forest-dwelling birds and arboreal forest birds — are among the most vulnerable. The silver lining in Audubon’s report – and a clarion call to action for us all – is that birds will fare much better if we can limit carbon release and hold temperature rise to 1.5oC. Seventy percent of species imperiled by a 3oC increase are spared under this mitigated scenario.
The new report also addresses the effects of warmer climate at both the state and county level. Under the higher-emissions scenario (3oC rise globally), we in Washington will see our warmest month increase by 6.2oC/11 o F and our coldest month by3.9oC/7 o F — in other words, our temperatures are projected to increase more than the global average in both summer and winter. And although we will experience several inches of additional rain each year, the increased temperature will result in a net loss of available moisture due to increased evaporation and uptake by plants. Climate change will result in habitat turnover across 30% of our state.As a result of changes here and in other locals, 141 of our 248 avian summer residents (56%) will lose more habitat than they gain, as will 56 of our 208 winter species (27%). If we can hold global temperature rise to 1.5oC, the number of climate threatened species drops to 96 (39%) and 29 (14%) in the summer and winter, respectively. A large portion of the climate stress experienced by Washington’s birds will be due to more extreme spring heat events and more heavy rains. Spring heat waves stress hatchlings, and heavy rains can flood nests and burrows and make it difficult for birds to forage and feed their young. In addition, sea level rise, increased numbers and intensity of forest fires, habitat loss due to expansion of cropland caused by changing microbiomes, and increased urbanization due to population displacement will cause further habitat loss.
A large portion of the climate stress experienced by Washington’s birds will be due to more extreme spring heat events and more heavy rains.
The birds in the tri-county region served by BHAS will not find themselves immune to climate stress. Birds in our local area are more likely to find their summer ranges affected than their winter ranges; as with the state as a whole, this is because many birds seen here have historically already lived in northern Canada or Alaska during the summer and they simply cannot go further north to avoid higher temperatures. If global annual temperatures climb by 3oC, changes in the availability of summer range will mean that our Black Hills region will risk losing 42 species of birds in one or more counties; 13 additional species may disappear due to loss of winter range. Nine of the species are at risk of losing large parts of both their summer and winter ranges.
Seventy percent of species imperiled by a 3o C increase are spared if we can limit carbon release and hold temperature rise to 1.5oC.
For those of you who want to get into the weeds, the following table details the effected birds. Tri-County Region Birds Threatened by a 3 Degrees Celsius Global Temperature Increase.
Fortunately, the situation is much mitigated if we act to hold global warming to 1.5 degrees Celsius. If we can do this, then the number of species whose summer ranges are threatened drops from 42 to 3 (Red-Breasted Sapsucker, Cassin’s Finch, and Barrow’s Goldeneye); the number of species whose winter ranges are threatened drops from 13 to 3 (Rock Sandpiper, Clark’s Nutcracker, and Grey-Crowned Rosy Finch). While the loss of any species is a tragedy, we clearly can make a tremendous difference by reducing our carbon footprint now.
Our marching orders are clear: in order to protect the birds we love, the environment as a whole, and ourselves we simply must substantially reduce carbon emissions. In order to hold to a 1.5oC temperature increase we cannot continue with “business as usual”; doing so puts us on track for the larger 3.0oC gain. Instead, it is imperative that we significantly reduce greenhouse gas emissions: we need to cut these emissions to 45% below 2010 levels by 2030 and we must reach net-zero carbon emissions by 2050. Net-zero emission levels does not require us to entirely stop releasing carbon into the air, but it does require us to offset our emissions by reforestation and other sequestration techniques and by using technology to pull greenhouse gases from the atmosphere.
Birds in our local area are more likely to find their summer ranges affected than their winter ranges.
These goals are attainable, but we must begin working towards them immediately. How? By reducing our reliance on coal and petroleum products and shifting to renewable energy sources. By instituting a tax on carbon usage or establishing a carbon cap and trade policy. By adopting energy-efficient machines and practices in our homes, offices, and factories. By ensuring that vehicles become more energy efficient, relying less on fossil fuels, and by expanding public transit. By reducing food waste and our heavy consumption of red meat. Surely each one of us can find numerous ways to personally contribute to the effort to mitigate climate change. Since there is an election coming up, we can start by voting for officials who intend to act on reducing climate change. I urge you to do all that you can to prevent the looming climate crisis while there is still time to do so. The birds around us – not to mention your children and grandchildren – will thank you.
The full report, “Survival by Degrees: 389 Bird Species on the Brink” can be found at https://nationalaudubon.app.box.com/s/ufr4lrt43s3przcmxghlm036n2tbteo4/file/536784078341.
