Glaciers are melting, sea levels are rising, cloud forests are dying, and wildlife is scrambling to keep pace. It’s becoming clear that humans have caused most of the past century’s warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.Global warming is the current increase in temperature of the Earth’s surface (both land and water) as well as it’s atmosphere. Average temperatures around the world have risen by 0.75°C (1.4°F) over the last 100 years about two thirds of this increase has occurred since 1975. In the past, when the Earth experienced increases in temperature it was the result of natural causes but today it is being caused by the accumulation of greenhouse gases in the atmosphere produced by human activities.
The natural greenhouse effect maintains the Earth’s temperature at a safe level making it possible for humans and many other lifeforms to exist.However, since the Industrial Revolution human activities have significantly enhanced the greenhouse effect causing the Earth’s average temperature to rise by almost 1°C. This is creating the global warming we see today. To put this increase in perspective it is important to understand that during the last ice age, a period of massive climate change, the average temperature change around the globe was only about 5°C.Greenhouse gases are produced both naturally and through human activities. Unfortunately, greenhouse gases generated by human activities are being added to the atmosphere at a much faster rate than any natural process can remove them.
Global warming is damaging the Earth’s climate as well as the physical environment. One of the most visible effects of global warming can be seen in the Arctic as glaciers, permafrost and sea ice are melting rapidly. Global warming is harming the environment in several ways including:
- Increased melting of snow and ice
- Sea level rise
- Stronger hurricanes and cyclones
Now, with concentrations of greenhouse gases rising, Earth’s remaining ice sheets (such as Greenland and Antarctica) are starting to melt too. The extra water could potentially raise sea levels significantly.As the mercury rises, the climate can change in unexpected ways. In addition to sea levels rising, weather can become more extreme. This means more intense major storms, more rain followed by longer and drier droughts (a challenge for growing crops), changes in the ranges in which plants and animals can live, and loss of water supplies that have historically come from glaciers.
by: Ammara Siddique