Understanding the Basics of Climate Change

Background on Climate Change

Let's take a look the basics here:

Positive feedbacks take place in long wave absorption and amplify the temperature change.

Negative feedbacks take place in the shortwave isolation and they reduce the size of the temperature change.

Just because it's positive does not mean it's good.

When we study science and the atmosphere, we learn about the positive and negative feedbacks. (For reference, Positive is bad and Negative is good.)These feedback responses in the atmosphere are Planck Feedback, Water Vapor, Albedo, and Clouds. All negative feedback take place in shortwave isolation due to the increase in water vapor which is based on increasing temperatures. If we increase our variables, such as the specific humidity in the air, it will increase because of the dependence of saturation vapor pressure on temperature. To balance the atmosphere, water vapor will increase, and this will lead to an increase in our surface temperature. Any changes in the Planck emission will influence the energy balance leading to further changes in temperatures. (I have added a supplemental page at the bottom for additional information.)

Explanation of how each feedback works.

Positive Feedbacks increase the equilibrium temperature change.

Negative Feedbacks decrease the temperature change.

Planck Feedback- Negative

This is one of the most important negative feedbacks; based on Planck’s law and the Stephan-Boltzmann law. Controls the surface temp. A warm planet radiates more warmth than a cold planet, and the increased temperature levels it radiates, the more energy it radiates outward to space.

Water Vapor- Positive

The increase of co2 gas increases the water vapor in the atmosphere. Water vapor also absorbs solar radiation and helps increase the heating of the atmosphere. The warmer the air the more water/moisture the atmosphere can hold.

Albedo – Positive

It’s the fraction of incoming radiation that is reflected. It increases the water content, and this acts as a positive. It can prompt infrared feedback.

With ice albedo the increase of ice would increase surface albedo and reflect more thus reducing the amount of solar energy absorbed by the planet.

Clouds- Negative

The presence of clouds in the atmosphere will lower the temperature due to its reflecting and absorbing ability. Clouds reflect Short Wave radiation and deep clouds lower Outgoing Longwave Radiation.

Positive feedback systems, increases the equilibrium temperature change. Negative feedback systems decrease the temperature change.

Water vapor is present in our atmosphere and works as a positive feedback. The increase of co2 gas increases the water vapor in the atmosphere. Water vapor also absorbs solar radiation and helps increase the heating of the atmosphere. This means the warmer the air, the more water/moisture the atmosphere can hold.

The earth needs to remain in a constant state of equilibrium. If we fall outside of this the earth will make up for the excess. The problem we have is when we release things like CO2, Methane, and aerosols into the atmosphere the earth has to balance this excess. The oceans then uptake the extra which in turn causes our oceans to warm. As you can see, we are in a constant state of trying to maintain balance. When we can no longer stay balanced we start to heat up. Greenhouse gases create a layer that traps heat causing us to warm faster.

What Does This Mean

The ratio between cumulative CO2 emissions and the consequent Global Surface Air Temperature increase is called the transient climate response to cumulative emissions (TREC) of CO2, and it falls in the 1.0°C – 2.3°C per 1000 PgC range. If Relative Humidity is constant, water vapor increases 7% for each degree of warming. (This is important to know and understand as we see a warming climate.) So, if we have a 2 degree increase in warming we will have a 14% increase in water vapor in the atmosphere. More water = more rain. This means we will see more floods, flash floods, heavy down pours, stronger and more intense hurricanes.

These are important factors to note when we are looking at what type of responses we are having and how it relates to climate change. Having a better understanding how the climate models and feedback systems work will further educate more people on the importance of climate change. Applying these climate concepts to public health will help us make better decisions and create a strategy to adapt to while mitigating climate change.

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