Imagine a greenhouse, complete with large glass panels on all surfaces. Solar energy passes through these panels and is used to warm the interior surface. The warm interior emits heat into the air, and the glass panes prevent the heat from escaping. Thus, warm temperatures remain within the glass boundaries. Earth's atmosphere acts like these glass walls.
Solar radiation penetrates the atmosphere and is absorbed by Earth's surface.
Maintaining appropriate gas concentrations stabilizes global temperatures at hospitable levels. Any shift in this complex system could change Earth's temperature, altering the planet's ability to sustain life, increasing the spread of infectious disease and setting the stage for other serious repercussions. For this reason, global temperature change and other trends in climate are worldwide concerns. Recent changes in temperature and atmospheric composition are indisputable, but interpreting these trends is another matter. Many experts cite Earth's impressive ability to adapt.