Climate change is a significant and lasting change in weather patterns in a particular area for decades to millions of years. Climate change has been a natural event that occurs on the Earth, such as glacial (ice-age) and non-glacial periods. These usually occur every 10,000 years and can be due to oceanic processes (such as oceanic circulation like El Niño–Southern Oscillation and the North Atlantic Drift), biotic processes, variations in solar radiation received by Earth, plate tectonics and volcanic eruptions, and human-induced alterations of the natural world. The latter effect are currently causing global warming which is contributing to climate change.
Expert scientists from all over the world agree that the average global temperature is increasing rapidly. This is due to the huge amount of gases that have been released into the atmosphere by modern ways of life. Burning fossil fuels creates carbon dioxide, an invisible gas which increases the greenhouse effect – the blanket of gases around the earth that keep the heat in. As we have burnt coal, oil and natural gas at increasing rates, our carbon dioxide emissions have risen, causing increasing rises in temperature.
What are the effects of Climate Change? We are already seeing the effects of climate change through severe droughts, flooding and reaching record temperatures (both high and low). People living on land close to sea level are feeling the effects of what seem like small increases in sea level as ice melts.
As Arctic ice melts the white surface that reflects heat well is replaced by dark sea which absorbs heat, which in turn speeds up the warming and melts more ice. Close to the Arctic Circle are thousands of miles of tundra – frozen ground that holds enormous quantities of methane, another much more powerful greenhouse gas. If this melts all the methane will be released, leading to more extreme warming.
The North-Atlantic Drift is an ocean circulation process by which warm sea water from the gulf of Mexico is blown by the wind toward the arctic, enroute the sea temperature drops and there is increasing salinity. These factors combined increase water density causing the water to flow back towards the Gulf of Mexico again in a so-called oceanic conveyor belt. As mentioned, increasing temperatures are causing the Arctic ice to melt. This melting ice can change the ratio of freshwater to salt in the sea. This would have a knock-on effect to the surrounding water density and in turn effect the North-Atlantic Drift ocean circulation. Much of Ireland’s weather is dependent on the North-Atlantic Drift, if this oceanic conveyor belt were to stop, freezing temperatures would hit Ireland and most of North Europe immediately. This in turn would result in a mini ice-age to occur.
Climate change is happening much more rapidly than anything caused by natural cycles, giving plants and animals little chance to adapt or migrate. This could be really critical if we think about key species such as insects that pollinate our crops, or our fish.
What can we do? One key recognition of Transition towns is that we need live respecting the biological limits of the planet. Many projects and proposals that have come from Transition towns are exploring ways we might do that. Imagine if we could design all our everyday activities so that they work more like plants or, even better, a woodland ecosystem. There are no waste bins in natural woodland – anything that is produced by one plant or creature is used by another, especially CO2!