The terms “weather” and “climate” are often used interchangeably but they refer to events with broadly different timescales.

What’s the difference between weather and climate?

Climate is a statistical and aggregate study of past weather conditions over a number of years — from decades to centuries. Weather, on the other hand, comprises the day-to-day changes in temperature, humidity, rainfall and wind that we experience.

Climate is often expressed in terms of months and seasons while weather is measured by days and weeks. While it is possible to provide weather forecasts, it is only possible to provide general projections for climate due to the wide time scales and uncertainties involved.

Then is global warming and climate change the same?

Not exactly!

The greenhouse effect occurs naturally when heat from the Earth’s surface is absorbed by greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).

Greenhouse gases are naturally present in the air, and allow the Earth’s atmosphere to be warm enough to support life. However, human activities such as burning of fossil fuels for energy and industrial production, and clearing of forests to raise livestock, increases the amount of GHGs in the atmosphere. These additional GHGs trap even more heat in the atmosphere, making the Earth warmer. Global warming leads to long-term climate change.

So what is climate change?

Climate change refers to significant variations in global weather patterns that persist over an extended period of time.

Over the past 100 years, global temperatures have been increasing faster than ever before. As the Earth gets warmer, rain patterns are changing, sea levels are rising, and year after year, snow and ice are melting sooner each spring. The impact of climate change on the environment is becoming increasingly apparent as climate conditions continue to change and intensify.

The consensus among the scientific community is that climate change is the result of a complex combination of natural and man-made activity. The findings of the United Nations’ Intergovernmental Panel on Climate Change (IPCC), an internationally accepted authority on climate change that provides comprehensive scientific assessments on climate change, indicate that human activities are indeed speeding up climate change.