How is the climate changing, and why?

How is our climate changing and what is causing this change? The climate has always been changing, but humans are now  warming the earth with the emission of greenhouse gases. Warmer temperatures, and other changes in the climate, are affecting sea levels, water quantity and quality, ecosystems, and people’s health and livelihoods.

Below is a selected list of high-quality resources that provide overviews of climate science information and highlight climate change impacts by sector.


Climate Science Overview

Intro: Climate Change Science

For those just getting started, an overview of climate changes and some potential impacts.

These short (~3 minute) videos explain past climate change, how humans are altering the climate system, and the impacts associated with these changes in the climate.
Video: Causes and Effects of Climate Change Video: National Climate Assessment: Climate Science

In-Depth: Climate Science

National Climate Assessment Report: Climate Science Supplement

The Climate Science Supplement appendix to the National Climate Assessment provides detailed information about how the climate is changing and why. It expands on the Our Changing Climate section by providing more details on what is happening to climate, how we know that these changes are mainly due to human activities, and what changes are projected for the future. The report can downloaded or viewed interactively on the website.
Report: Climate Science

Swinomish Tribal Lands

FAQ: Climate Change Science

For those who want more details, websites with frequently asked questions about climate science.

Below are links to some websites with frequently asked questions (FAQs) about how the climate is changing, what is causing these changes, and potential impacts.
National Oceanic and Atmospheric Administration FAQsNational Climate Assessment FAQs

In-Depth: Climate Science

For those who want a deep dive on climate changes and impacts to specific ecosystems.

Detailed summary reports and materials that provide an overview of how climate is changing, as well as in-depth discussion of the observed and projected impacts. Videos on specific impacts, aligned with chapters in the National Climate Assessment, provide information on more specific topics.
Video: Climate Change and HealthVideo: Climate and Oceans



Climate Change Impacts by Sector

Impacts: Forests

National Climate Assessment: Forest Chapter

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of climate change on different sectors and ecosystems across the U.S. These include impacts to the natural environment, as well as resources that humans depend on. The chapter on forests explains how climate change is increasing the vulnerability of many U.S. forests. Information can be viewed interactively on the website or the chapter can be downloaded.
Forest Chapter
Swinomish Tribal Lands

Impacts: Ecosystems

National Climate Assessment: Ecosystems, Biodiversity, and Ecosystem Services Chapter

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of climate change on different sectors and ecosystems across the U.S. These include impacts to the natural environment, as well as resources that humans depend on. The chapter on ecosystems includes the following: Impacts of climate change on ecosystems reduce their ability to improve water quality and regulate water flows. Rapid changes to ecosystems may cause the displacement or loss of many species. Timing of critical biological events is shifting, affecting species and habitats. Information can be viewed interactively on the website or the chapter can be downloaded.
Ecosystems Chapter

Impacts: Human Health

National Climate Assessment Chapter: Human Health Impacts

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of climate change on different sectors and ecosystems across the U.S. The chapter on human health explores how climate change threatens human well-being, including impacts from increased extreme weather events, wildfire, decreased air quality, and illnesses transmitted by food, water, and diseases carriers such as mosquitoes and ticks. Information can be viewed interactively on the website or the chapter can be downloaded.
Human Health HighlightsHuman Health Report

Impacts: Energy, Water, Land

National Climate Assessment Chapter: Energy, Water, Land Impacts

The Energy, Water, and Land chapter of the National Climate Assessment explores how climate change affects energy, water, and land use as well as the interactions among these sectors. Information can be viewed interactively on the website or the chapter can be downloaded.
Report: Energy, Water, Land



Resources describing the impacts of climate change in the Northwest

Impacts: Northwest

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of clima

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of climate change on different regions of the U.S. The information can be viewed interactively on the website or the regional chapter can be downloaded. The chapters contain information on impacts to natural systems, as well as impacts on human systems and infrastructure.
Northwest Region HighlightsNorthwest Region Report

State of Knowledge: WA State

Washington State of Knowledge Report – Climate Change Impacts and Adaptation in Washington State

Climate Change Impacts and Adaptation in Washington State: Technical Summaries for Decision Makers summarizes existing knowledge about the likely effects of climate change on Washington State and the Pacific Northwest, with an emphasis on research since 2007.

This “State of Knowledge” report provides technical summaries detailing observed and projected changes for Washington’s climate, water resources, forests, species and ecosystems, coasts and ocean, infrastructure, agriculture, and human health in an easy-to-read summary format designed to complement the foundational literature from which it draws. The report also describes climate change adaptation activities underway across the state and data resources available to support local adaptation efforts.
State of Knowledge

State of Knowledge:Puget Sound

State of Knowledge Report – Climate Change in Puget Sound

This report is designed to serve as a reference for individuals interested in understanding the state of the science on climate change and its effects within the Puget Sound region. This report summarizes the current state of knowledge concerning observed and likely future climate trends and their effects on the lands, water and people of the Puget Sound region.
State of Knowledge


Resources describing the impacts of climate change in the Southwest

Impacts: Southwest

National Climate Assessment: Southwest Region

The National Climate Assessment (NCA) includes chapters that summarize the expected impacts of climate change on different regions of the U.S. The information can be viewed interactively on the website or the regional chapter can be downloaded. The chapters contain information on impacts to natural systems, as well as impacts on human systems and infrastructure.
Southwest Region HighlightsSouthwest Region Report

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