Climate change is happening now and affecting the things we love. As part of Show The Love week we are looking at how nature, in particular seas and seabirds around Scotland’s coasts, is being affected. In this first blog Peadar O’Connell unpicks exactly what climate change is and why it is such a threat to our much loved wildlife. Keep an eye for more blogs over the next week.
Show The Love – what is climate change?
Weather is something that changes daily. Climate, however, is the longer term weather patterns for a certain place during a particular period – Scottish winters should be cold and summers warm. You can scale this up to the global level where the average temperatures can be measured and compared to other years, which is important for monitoring global temperatures.
In the past the climate has changed many times causing cold and warm periods over thousands of years. The difference between these natural fluctuations and what is happening now is the unprecedented speed it is happening at. Wildlife has been able to adapt in the past to the slow changes but now we’re incredibly worried for our species and habitats ability to keep up with the pace of change.
The last great ice age ended when the global temperatures rose over a period of millennia (1000 years), and meant the life that existed in the colder parts of the planet had some time to adapt: some, like reindeer moved north, others, like the mammoth, became extinct (although hunting may also have played a part in this) whilst many adapted to cope under milder conditions over time.
Today the average global temperature has increased by about 1 degree C in the last hundred years with most of that happening in the past 50 years (Fig 1). Depending on how we respond it is predicted to increase by between 1.5C and 5C degrees in the next 80 years! It would be an extreme challenge for nature to adapt this quickly, especially as habitats are far more fragmented and isolated due to previous losses. The disaster currently faced by polar bears in the arctic as their habitat changes is similar to the problems faced here in Scotland by mountain hare, common scoter and delicate alpine flowers. All could be lost from Scotland in years to come if they can’t adapt or move.
Figure 1: Average global temperatures since 1850-2017 showing a 1 degree increase since the 1900s
Credit: https://www.metoffice.gov.uk/research/monitoring/climate/surface-temperature
Speed of change
So why is the climate warming so quickly? The short answer is greenhouse gases. CO2 or carbon dioxide is the one we hear most about because there is so much of it. Greenhouse gases occur naturally but the more greenhouse gases you have in the atmosphere the more heat that gets trapped and hence the more the planet warms. If we look again at the last ice age, temperatures increased after a rise in the CO2 in the atmosphere from 180 parts per million to 260 parts per million before the industrial revolution. CO2 levels in the atmosphere have now topped 400 and are still rising! (see fig 2 and 3). As seen in fig 2 this increase is particularly evident from the 1950s onwards when there was an increase in industrialisation.
Fig 2: Indirect measurements of the fluctuations and recent huge increase in CO2 in the atmosphere over the last 400,000 years - Data source: Reconstruction from ice cores.
Credit: https://climate.nasa.gov/vital-signs/carbon-dioxide/
Fig 3: CO2 increase between 2005 and 2017
The excess CO2 that is being pumped into the atmosphere on a daily basis is coming primarily from the burning of fossil fuels like oil, coal and gas. Fossil fuels include the remains of organic life (all life on earth is carbon based) that lived millions of years ago and release large stores of CO2 when burnt. Burning these fuels has given our ancestors and now us the energy we need to build and maintain our current lifestyles, but if we continue to burn them our children and grandchildren will live in a much different and more challenging world.
Image by Ben Hall (rspb-images.com)
Impacts of climate change – what can you do?
In addition to the trends, such as warming oceans and sea level rise, climate change is causing more extreme weather events as the warmer atmosphere and oceans hold more energy and create more powerful weather events – remember last year’s massive hurricanes Harvey, Irma and Maria?
Warming and extreme weather are leading to changes in the farmed and natural environment. The food we can grow will change, as will the fish we catch and eat. Wild animals and plants will have to adapt or risk extinction, disease and alien pest species are predicted to become more common, including those affecting commercial industries like forestry and farming. This could all lead to societal changes including mass migration from areas in the world worst affected.
The bottom line is that the impacts are already happening and are set to get worse so there is a genuine and urgent need to take action now. All the things we love are affected - we don’t want to lose the things important to us because of climate change. Over the next week why not show the love for the things you hold dear? Go to www.showthelove.org.uk to find out what you can do.