Changes can be considered as being naturally occurring or anthropogenic—that is, resulting from human activity. Which of the following changes are anthropogenic?  

[Climate Change While we can physically measure the current levels of carbon dioxide, to estimate future concentrations, we have to employ computer models. On the graph below, we can see the marked increase in CO2 since the industrial revolution. This includes the observed CO2 concentration for 2018 and two predictive points based on a low-emissions and high-emissions model. If you were creating a model to estimate future CO2 concentrations, which of the following would you consider?

Differentiation led to the Earth separating into layers based on density. Drag the layer labels to the correct locations on the triangular schematic of Earth’s interior below.

Another anthropogenic change the Earth experiences is pollution. Match the type of pollution with the anthropogenic cause.  

Real-world systems are often complex and are where natural and anthropogenic influences interact. The carbon cycle is one such system. There are processes, both human-made and natural, that release carbon into the atmosphere. There are processes in which carbon is absorbed from the atmosphere. On the image below, select the processes that absorb carbon dioxide from the atmosphere.

Greenhouse gases are atmospheric gases that affect the Earth’s temperature by absorbing infrared radiation. Combustion of fossil fuels increases greenhouse gas emissions. These emissions are one of the primary drivers of the warming trend we have identified in Earth’s climate. From the list of gases below, select the gases that are considered greenhouse gases.

The harvesting of trees for wood and paper resources is a necessary part of our current lifestyle. However, deforestation has become a significant problem, especially when we consider the vast tracks of land cleared in the Amazon as part of slash-and-burn agriculture. These satellite images highlight areas that have undergone deforestation near Ariquemes, Brazil. Which of the following environmental conditions are the result of deforestation?

Whereas spectral classes describe a star’s surface temperature, the absolute magnitude of a star describes the star’s true brightness, or luminosity. The image below shows the same 60-watt lightbulb at various distances from the viewer. Which of the following statements accurately describes the magnitude of the lightbulbs as shown?

It is pretty clear that the Earth is warming and will likely do so for the foreseeable future. But why should we care? What does a warming actually mean for humanity?

Using the tools mentioned in the previous question and through direct sampling, climatologists have directly measured atmospheric CO2 over the past 60 years. Notice the annual oscillations of carbon dioxide. What causes this repetitive change?