Greenhouse gases are a natural part of the atmosphere. They absorb and re-radiate the sun’s warmth, and maintain the Earth’s surface temperature at a level necessary to support life. The problem we now face is that human actions — particularly burning fossil fuels (coal, oil and natural gas), agriculture and land clearing — are increasing the concentrations of the gases that trap heat.

Greater concentrations of greenhouse gases will trap more heat and raise the Earth’s surface temperature. This is the enhanced greenhouse effect, which is the process behind climate change.

“Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750.” — IPCC Climate Change 2007: The Physical Science Basis, Summary for Policy Makers. The increases in greenhouse gases can be attributed to fossil fuel use, land-use change and agriculture.

Climate Change Impacts on Western Port

The former Western Port Greenhouse Alliance (now SECCCA) worked with the Victorian Department of Sustainability and Environment (DSE) and the CSIRO to determine the impacts of climate change on the Western Port region. Below is a summary of projected changes.

Summary of projected climate changes for Western Port

Temperature

annual warming of 0.2 to 1.4°C by 2030 and 0.7 to 4.3°C by 2070

day time maximum temperatures and night time minimum temperatures will rise at a similar rate

warming will be similar throughout the seasons

a 10 to 40% increase in the number of hot summer days (over 35°C) by 2030 and a 20 to 300% increase by 2070

a substantial reduction in the number of frost days by 2030 and a possible loss of all frost days by 2070