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    1. Climate Feedbacks Climate feedbacks are natural processes that respond to global warming by offsetting or further increasing change in the climate system. Feedbacks that offset the change in climate are called negative feedbacks. Feedbacks that amplify changes are called positive feedbacks. Water vapor appears to cause the most important positive feedback. As the earth warms, the rate of evaporation and the amount of water vapor in the air both increase. Because water vapor is a greenhouse gas, this leads to further warming. The melting of Arctic sea ice is another example of a positive climate feedback. As temperatures rise, sea ice retreats. The loss of ice exposes the underlying sea surface, which is darker and absorbs more sunlight than ice, increasing the total amount of warming. Less snow cover during warm winters has a similar effect. Clouds can have both warming and cooling effects on climate. They cool the planet by reflecting sunlight during the day, and they warm the planet by slowing the escape of heat to space (this is most apparent at night, as cloudy nights are usually warmer than clear nights).Climate change can lead to changes in the coverage, altitude, and reflectivity of clouds. These changes can then either amplify (positive feedback) or dampen (negative feedback) the original change. The net effect of these changes is likely an amplifying, or positive, feedback due mainly to increasing altitude of high clouds in the tropics, which makes them better able to trap heat, and reductions in coverage of lower-level clouds in the mid-latitudes, which reduces the amount of sunlight they reflect. The magnitude of this feedback is uncertain due to the complex nature of cloud/climate interactions.9

      Lastly, the webpage also contains distinguishable and readable content. Almost the entirety of the article is done with black text over a white background making it clearly readable, whereas the images and videos are placed in a proper manner far apart from the text without making it all clumped up.

    2. Key Greenhouse Gases

      The webpage also includes a video titled "The Greenhouse Effect" (Right above the highlighted title). This video shows commendable web accessbility practice as the video has closed captioning on videos, and the important sounds and contexts are communicated nicely.

    3. The greenhouse effect helps trap heat from the sun, which keeps the temperature on earth comfortable. But people’s activities are increasing the amount of heat-trapping greenhouse gases in the atmosphere, causing the earth to warm up.

      The article also has images and videos. These are very important to consider when looking at web accessiblity because these types of media need to be accessible to different users. (Images and videos can make it accessble to a larger visual audience).

    4. Basics of Climate Change Learn about some of the key concepts related to climate change: The Greenhouse Effect Key Greenhouse Gases Other Greenhouse Gases Aerosols Climate Feedbacks

      The webpage has the information organized using clear and proper heading and subheadings. The linked subheadings take the user to their preferred topic about climate change, and make it very easy for them to navigate and understand the entire article. Nice web accessbility practice!