FEEDBACK FEEDBACK POSITIVE Feedback with climate change Orbital

FEEDBACK

POSITIVE Feedback with climate change. • Orbital forcing leads to a warmer Northern Hemisphere which causes ice sheets to melt. • POSITIVE FEEDBACK – Darker color of the water and ground exposed absorbs more solar energy and warms further. • This cycles continues.

Activity • Describe an event in your life that causes Positive Feedback. • Draw and label a diagram of the process.

More Positive Feedback with climate change. • Orbital forcing leads to a warmer Northern Hemisphere which causes the oceans to warm. • POSITIVE FEEDBACK - As the oceans warm, they release CO 2 into the atmosphere, which increases the greenhouse effect and further increases the warming. • The cycle continues.

More Positive Feedback with climate change. • Orbital forcing leads to a warmer Northern Hemisphere which causes the oceans to warm. • POSITIVE FEEDBACK - As the oceans warm and more plants invade the previously glaciated areas, evaporation and transpiration of water increase the water vapor in the atmosphere. Water vapor is another greenhouse gas and further increases the warming. • The cycle continues.

NEGATIVE Feedback with climate change. • Orbital forcing leads to a warmer Northern Hemisphere which causes the oceans to warm and evaporate more water. • NEGATIVE FEEDBACK - higher amounts of water vapor in the atmosphere can lead to increased cloud formation. The clouds reflect sunlight back into space and are opaque because the water droplets that form the cloud scatter the incoming light, thus further decreasing the amount that reaches the surface. • The cycle is reduced.

Activity • Describe an event in your life that causes Negative Feedback. • Draw and label a diagram of the process.

NEGATIVE Feedback with climate change. • Orbital forcing leads to a warmer Northern Hemisphere which causes the oceans to warm and release more CO 2. • NEGATIVE FEEDBACK - higher amounts of carbon dioxide cause forests to flourish. More plants consume CO 2 and reduce the quantity of greenhouse gases in the atmosphere, lowering the amount of radiative forcing. • The cycle is reduced.