The last major section from the EPA’s new Climate Change Indicators in the US report is society and ecosystems. Below are key summary points.
Clear changes in growing seasons, bird migration leaf growth and blooming dates have occurred and the trends suggest that they will continue. Heat-related deaths show much more variability, despite clear heating trends, but that could be due to a variety of factors beyond climate change that have an influence on this topic.
The following text comes directly from the US EPA’s “Summary of Key Findings” [PDF]:
Society and Ecosystems
Heat-Related Deaths. Over the past three decades, more than 6,000 deaths across the United States were caused by heat-related illness such as heat stroke. However, considerable year-to-year variability makes it difficult to determine long-term trends.
Length of Growing Season. The average length of the growing season in the lower 48 states has increased by about two weeks since the beginning of the 20th century. A particularly large and steady increase has occurred over the last 30 years. The observed changes reflect earlier spring warming as well as later arrival of fall frosts. The length of the growing season has increased more rapidly in the West than in the East.
Plant Hardiness Zones. Winter low temperatures are a major factor in determining which plants can survive in a particular area. Plant hardiness zones have shifted noticeably northward since 1990, reflecting higher winter temperatures in most parts of the country. Large portions of several states have warmed by at least one hardiness zone.
Leaf and Bloom Dates. Leaf growth and flower blooms are examples of natural events whose timing can be influenced by climate change. Observations of lilacs and honeysuckles in the lower 48 states suggest that leaf growth is now occurring a few days earlier than it did in the early 1900s. Lilacs and honeysuckles are also blooming slightly earlier than in the past, but it is difficult to determine whether this change is statistically meaningful.
Bird Wintering Ranges. Some birds shift their range or alter their migration habits to adapt to changes in temperature or other environmental conditions. Long-term studies have found that bird species in North America have shifted their wintering grounds northward by an average of 35 miles since 1966, with a few species shifting by several hundred miles. On average, bird species have also moved their wintering grounds farther from the coast, consistent with rising inland temperatures.
For more detailed information on climate change issues concerning society and ecosystems, visit the EPA’s Society and Ecosystems PDF.
Beyond what we have reported here on Planetsave, more resources are on the EPA’s Climate Change Indicators in the U.S. webpage and here are a few more key links:
- Press Release (27 April 2010) from EPA: EPA Issues Report on U.S. Climate Change Indicators.
- Report Slideshow
- Full Report (PDF) (80 pp, 13.2MB)