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What is Climate Change?

Climate change affects communities, our economy, and our health in various ways. If we do not take action against climate change now, the results will be disastrous.

 

Climate change and global warming refer to the increase in average global temperatures. Human activities and certain natural events are contributing factors to the increase in average global temperatures.

Global warming is mainly caused by the increase in “greenhouse” gases like Carbon Dioxide (CO2). A warming Earth leads to a series of changes in climate, affecting mankind and wildlife in many ways.

 

Causes of Global Warming

CO2and other air pollutants accumulate in the Earth’s atmosphere like a thickening blanket that traps the sun’s heat and warms the planet.

There are many causative factors to global warming. This includes:

  • changes in the greenhouse effect, which directly affects the amount of heat absorbed by the planet’s atmosphere;
  • changes in the sun’s energy reaching Earth; and
  • variations in the reflectivity of Earth’s atmosphere and surface.

 

In the United States, power plants that burn coal are the largest source of CO2pollution. These power plants produce a staggering 2.5 billion tons of CO2every single year.

Automobiles are the second largest source of CO2,creating roughly 1.5 billion tons a year.

 

Signs of Climate Change

  • Sea and ocean levels

Perhaps one of the best indicators of climate change is the amount of heat being stored in Earth’s bodies of water. In the recent years, the heat content in the world’s seas and oceans has increased, accounting for more than 90% of the total heat accumulated by the land, air, and ocean since the 1970s. Sea and ocean warming continues to this day, especially in the top several hundred metres to the surface. Global sea levels have increased at an average rate of 1.8 mm annually from1960 to 2003. This rate has significantly risen to around 3.2 mm annually from 1993 to 2012. The rates of sea levels may not be the same around the world and may vary from year to year. Ocean currents are also changing, especially in the Southern Ocean. Scientists reveal that a significant reduction in the coldest deep ocean water (also called Antarctic Bottom Water) has been observed over the past few decades. Earth’s deep ocean currents play a vital role in the distribution of heat and carbon around the world, thus regulating the climate.

 

  • Rise in air temperatures

On a global scale, air temperatures have increased by roughly 0.85 °C since the late 1800s, with most of the global warming occurring during the 1970s. In Australia, the annual average daily mean temperatures have increased by 0.9 °C since the year 1910, with each passing decade getting warmer than the previous decade since the 1950s. The country has observed a decrease in the number of cold days, and an increase in warm days, with more than double the number of hot days recorded since the 1960s.

 

  • Extreme weather

Extreme weather events refer to tropical cyclones, heat waves, bushfires, cold snaps, heavy rainfall, and droughts. More and more evidence show the increasing intensity and frequency of many extreme weather conditions. Individual extreme events occur as a result of a number of contributing climatic factors. It may be difficult to isolate the role of climate change in any given event, but there are many studies that show climate change’s role in specific extreme weather conditions.

 

  • Rainfall patterns

Even rainfall patterns are changing due to climate change. Scientists have shown that the global water cycle continues to intensify with a warming planet, meaning wet regions are likely to get wetter and dry areas likely to get drier due to climate change.

 

A Cause for Serious Concern

Global warming is a complex phenomenon; an environmental and humanitarian crisis with full-scale impacts that are difficult to predict in advance. Each year, however, scientists from around the globe get to learn more about how this phenomenon affects our planet, many of whom agree that certain consequences are likely to take place if current trends continue. Among these are:

  • the glaciers that continue to melt, early snowmelt, and severe droughts that cause dramatic water shortages in some countries;
  • rising sea levels that lead to coastal flooding;
  • warmer sea surface temperatures that bolster more intense hurricane/typhoons;
  • new pests and more mosquito-borne diseases that plague forests, farms, and cities; and
  • disruption of natural habitats like coral reefs, forests, and alpine meadows that could drive many species to extinction.

 

The Earth is Getting Hotter

Local temperatures may fluctuate naturally, but for the past five decades, the average global temperature has risen at an alarming rate. Studies have shown that the trend will continue to accelerate in the years to come, with the 10 hottest years on recorded history having occurred in the 1990s.

According to some scientists, if we do not curb global warming emissions, global temperatures, particularly in the US, could be 3 to 9 degrees higher by the turn of the century.

 

Worst Case Scenario

A rise in temperature of just 2°C would potentially cause:

  • severe storms and flooding in certain countries, and droughts in others
  • acidic seas that could kill marine life and destroy food chains
  • little or no Arctic sea ice during the summer season, which is detrimental for animals like the polar bears; and could also hasten global warming due to less polar ice that deflects sunlight

 

If we continue to ignore the possible consequences of climate change and global warming, scientists have predicted possible increments of up to 6°C this century.

So beyond 2°C, it’s almost unimaginable what the scenario would be:

  • rainforest will die
  • increased melting of the ancient ice sheets in Antarctica and Greenland
  • substantial increase in sea levels
  • humans and wildlife suffering along the way

 

Must we continue to ignore climate change? We must act now.