Whereas weather is the daily to seasonal changes in patterns of temperature, precipitation, humidity, and wind; climate change is the long-term trend of these patterns. Some short-term climate variation is normal from cycles of the Pacific Decadal Oscillation and El Niño-Southern Oscillation; however, natural causes and natural variability alone cannot explain the rapid increase in global temperatures in the last 50 years. A chief cause, say scientists, is the rise in global greenhouse gases due to human activity. This range of natural and human factors driving the warming or cooling influences on global climate plays an essential role in shaping ecosystems, including Puget Sound.
Sources:
Puget Sound Science Review
http://www.eopugetsound.org/science-review/section-2-driver-climate-change-salish-sea-ecosystem
Overview
A 2015 report from the University of Washington provides the most comprehensive assessment to date of the expected impacts of climate change on the Puget Sound region.
![All scenarios project warming for the 21st century. The graph shows average yearly temperatures for the Pacific Northwest relative to the average for 1950-1999 (gray horizontal line). The black line shows the average simulated temperature for 1950–2011, while the grey lines show individual model results for the same time period. Thin colored lines show individual model projections for two emissions scenarios (low: RCP 4.5, and high: RCP 8.5)[ ], and thick colored lines show the average among models projecti](/sites/default/files/styles/large/public/topical_article/images/TempChangeGraph.png?itok=kXP4zi8H "All scenarios project warming for the 21st century. The graph shows average yearly temperatures for the Pacific Northwest relative to the average for 1950-1999 (gray horizontal line). The black line shows the average simulated temperature for 1950–2011, while the grey lines show individual model results for the same time period. Thin colored lines show individual model projections for two emissions scenarios (low: RCP 4.5, and high: RCP 8.5)[ ], and thick colored lines show the average among models projections for each scenario. Bars to the right of the plot show the mean, minimum, and maximum change projected for each of the four emissions scenarios for 2081-2100, ranging from a very low (RCP 2.6) to a high (RCP 8.5) scenario. Note that the bars are lower than the endpoints from the graph, because they represent the average for the final two decades of the century, rather than the final value at 2100. Figure source: Climate Impacts Group, based on climate projections used in the IPCC 2013 report.")
