Final answer:
Global warming refers to the rise in Earth's average surface temperature due to increased greenhouse gas concentrations in the atmosphere, which enhances the greenhouse effect and leads to climate change. This change is primarily human-induced and includes shifting weather patterns and effects on the ecosystem.
Step-by-step explanation:
Global warming is characterized by an increase in the Earth's average surface temperature due to the rise of greenhouse gases in the Earth's atmosphere. The phenomenon heightens the greenhouse effect, which is a natural process that warms the Earth's surface. When the sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. An excess of these gases can cause the atmosphere to trap more heat, leading to a rise in surface temperatures.
Climate change encompasses not only the warming driven by human activities, such as the emission of greenhouse gases from the burning of fossil fuels but also the resulting large-scale shifts in weather patterns. Even though climate change can manifest as both higher and lower temperatures in the short term, the long trend is a warming of the planet, which is often referred to as global warming. Examples of the effects of this climatic change include shifts in marine populations due to rising ocean temperatures and the potentially devastating melting of the Antarctic ice sheet.
It's crucial to understand that the rise in Earth's temperature over the past century is relatively small, around 1°C (about 1.3°F), yet even such a seemingly marginal increase can have significant environmental impacts. The consistency of global temperature and climate is essential for species and their habitats, and abrupt changes can lead to stress that might be unsustainable for some ecosystems and organisms, indicating the seriousness of global warming and its consequences for our planet.
The correct answer to the original question, which is about the phenomenon causing an undesirable change in the climate due to an increase in Earth's average temperature, is A) Global warming.