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released , greenhouse gases are trapped in atmosphere , temperature heats up even more , more permafrost melts and more greenhouse gases are released . And slowly , but surely , the planet starts to heat up .
Why is this an issue ?
Well , as the permafrost melts , several issues begin to occur . Where the permafrost previously lay underneath steady , hard land due to it providing a solid base , and as it melts things such as erosion , disappearance of lakes , landslides and habitats being destroyed occur . And then there are also the added problems caused by climate change such as sea levels rising , increased risks of droughts , flooding , extreme weather and forest fires along with rising temperatures . And all of this occurs because of the release of greenhouse gases .
This is because greenhouse gases trap heat , so when we emit it from our cars and things such as fossil fuel burning plants and it gets trapped by the atmosphere , once too much gets up there , Earth can begin to heat up . More specifically this is because GHGs are nearly transparent to solar radiation , so the radiation from the sun can enter easily , but it is practically opaque to to thermal radiation that is emitted back by the Earth . This means that the the sun ’ s radiation can enter and heat the Earth , and in turn the Earth emits a portion of the energy back into space in the form of longer wavelengths than what the solar radiation was . The GHGs then absorbs and reradiates the heat molecules back down to Earth so we have additional heat energy . So then , the Earth begins to heat up . And because of this heating and the problems that it causes , such as extreme weather , droughts and floods , our organisms in New Zealand begin to become affected
What is the science behind the increase of droughts , flooding and extreme weather ?
Flooding and Droughts : Why flooding is increased by global warming relies on firstly , on what feeds rain . This being water vapour , but to find the actual reason we have to first look into where the water vapour comes from . Around 60 % of the water vapour comes straight from our oceans as it evaporates off the surface . The other 40 % is known as being “ recycled ” over continents . As an example , you need only to look at China : China , gets most of its rain from evaporation over Eurasia .