Normal climate changes are being affected by a gradual increase in the levels of greenhouse gases around the earth’s atmosphere. This could see a rise in sea levels and changes in climate patterns, increasing the number of storms, rain, coastal flooding and erosion in the region.
Greenhouse gases naturally form a ‘blanket’ around our atmosphere, warming the Earth by trapping some of the heat usually radiated back into space. If it becomes too thick, too much heat becomes trapped. This creates the so-called ‘Greenhouse Effect’ which may lead to global warming.
These ‘greenhouse gases’ have been accumulating over the last 200 years, due to increased growth in human and industrial activities. The temperature of the Earth is increasing (‘global warming’), affecting weather patterns world wide. Extreme changes in weather increases the risk of flooding and erosion.
The Waikato region tends to have warm, humid summers and mild winters, with prevailing west and south-west winds from the Tasman Sea. While no part of the region is more than 80 km from the sea, extreme hot and cold temperatures can occur in some sheltered and elevated areas inland. Our average rainfall is 1,250 mm, however rain is heavier in Coromandel Peninsula, Waitomo/Kawhia and the alpine area of Tongariro National Park. Rainfall is less in the lower Waikato lowlands, Hauraki Plains, Taupo behind the Hauhungaroa Range and Reporoa Valley behind the Paeroa Range.
Find out more about the Waikato region’s climate.
Industry, agriculture, households and transport all produce greenhouse gases, including:
New Zealand is unique in that over half (55 percent) of all greenhouse gases produced in this country are non-carbon dioxide (non-CO2). Forty percent of greenhouse gases produced in 1998 were methane and nitrous oxide emissions from cattle, sheep and other domestic livestock. These are more likely to have a greater effect than carbon dioxide on climate change.
Greenhouse gases are also produced by:
Other sources include landfills, wastewater treatment facilities, land use changes (for example to grazed pasture), fertiliser use and peatland drainage. Carbon dioxide is also released from the carbon stores in trees when forests are destroyed. This means we lose forests as valuable carbon ‘sinks’, which help to soak up greenhouse gases.
Increase in the amount and frequency of rainfall could cause more river flooding in some areas of the Waikato region, while decreases may cause drought. Land use, such as cropping and forestry may need to change to suit new weather patterns, affecting runoff, hillside and valley drainage as well as increasing fire risks due to vegetation changes. The location of some industries, agriculture, horticulture and tourism may also need to change.
Changing weather patterns may also threaten biodiversity, affecting our ecosystems. Species that are already under threat or at the limit of their climatic range may not be able to survive. New diseases and pests may take hold. Tropical pests and tropical diseases like malaria may become established in areas where they currently do not exist.
Predicted sea level rise could push the sea inland by almost 90 metres (nearly the length of a rugby field), affecting low-lying areas and estuaries. This will influence where people live, work and play and put even more pressure on our coastal environment.
Landslides may be triggered by heavy rain, as much of the soil through the Waikato region is volcanic and prone to erosion. People relocating inland to avoid coastal hazards such as flooding and erosion may face an increased risk of large scale rock and/or soil slips in marginal areas, due to the effects of changes in rainfall, drainage patterns and land use on hill slopes.
These events also threaten ‘lifeline’ services such as water, power, telecommunication and transportation networks. Find out more about managing lifelines(external link) to deal with unexpected emergency or natural hazard events.
You can help reduce greenhouse gas emissions by not using aerosols that contain greenhouse gases. Be energy efficient by:
Think about how you and your family and friends get around:
Reduce carbon dioxide in our air:
The New Zealand Government has signed and ratified the Kyoto Protocol and the United Nations Framework Convention on Climate Change(external link) (UNFCCC):
Find out about New Zealand policies that aim to mitigate the effects of climate change through the Government’s New Zealand Climate Change Project(external link).