What are the similarities and differences between an actuz greenhouse and the gaseous atmospheric greenhouse? Why is Earth's greenhouse effect changing?

To understand the Earth's greenhouse effect, we must first tackle the concept of greenhouse gases (GHGs). These gases, which include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor, largely determine the thermal state of our atmosphere.

Like a blanket, GHGs absorb and emit infrared radiation, creating a warm layer that surrounds the Earth and ensures that our planet maintains an average temperature that can support life. This process is essential for warmth and is the same basic principle that a gardener uses in a physical greenhouse to keep plants from freezing.

The balance of these gases is crucial. However, human activities, like burning fossil fuels for energy and transportation, significantly increase the concentration of these gases, leading to more heat being trapped in the atmosphere. Additionally, certain industrial processes and agricultural practices also emit GHGs, altering the natural balance that has sustained life on Earth for millennia.

Global warming is directly related to the increase in greenhouse gases in our atmosphere. As the concentration of these gases rises, more infrared radiation is trapped, leading to an overall increase in Earth's average surface temperature.

Though the terms are sometimes used interchangeably with climate change, global warming specifically refers to this increase in surface temperature. Its effects can be wide-ranging and severe, from melting polar ice caps and rising sea levels to more extreme weather events like hurricanes and droughts.

Scientists track global temperature changes and CO2 levels meticulously, and the trends have consistently shown an upward trajectory over the past century. This warmth doesn't just affect climate; it can influence ecosystems, wildlife distributions, and even human health and agriculture. The understanding of global warming has led to international efforts to reduce GHG emissions, such as the Paris Agreement.

When discussing the Earth's greenhouse effect, it is crucial to understand infrared radiation. In essence, this is a type of energy that is part of the electromagnetic spectrum, which includes other types of energy like visible light and ultraviolet radiation.

Infrared radiation is not visible to the human eye, but we can feel it as heat. The Sun emits a broad spectrum of radiation, including infrared, but when it reaches Earth's surface, some of it is absorbed and then reradiated as longer-wavelength, lower-energy infrared radiation.

Greenhouse gases are particularly good at absorbing this type of radiation, and they then re-emit it in all directions, including back towards the Earth's surface. This process is the backbone of the greenhouse effect, providing the warmth our planet needs. However, with the increased concentrations of GHGs, too much infrared radiation is being trapped, leading to the aforementioned global warming.