Why two degrees?

When people realise I am studying for a Masters in Climate Change I am often asked ‘What would you say to someone who doesn’t believe in climate change?’, I must say it often stumps me when I’m put on the spot and I generally end up rambling on about observations and datasets until they wish they’d never asked. However, the question surprises me as I am from a physical geography background and wholeheartedly agree with the Intergovernmental Panel on Climate Change (IPCC) conclusions that the ‘human influence on the climate system is clear’. A recent study by Cook et al., 2016 concisely summed up the views of the scientific community, finding 97% were in agreement that the current climate change is a result of human causes.

In comparison, imagine the world as a person; a person who is experiencing a range of new health problems which are gradually getting worse at a rate they had not experienced before. Consequently, they go to the doctors. If 97% of doctors reported they required treatment I assume most people would take the treatment; I know I certainly would. However, if you would consider yourself in the group who would not, then this may not be the blog for you, as I will be focusing on the next step. The step where we ask the big questions. How long until it is too late? What are the treatments? Are there any side effects?

How long (or hot) until it is too late?

Since pre-industrial times, global temperatures have increased approximately 1°C. This may not sound like a huge amount, but the predictions made by the IPCC indicate an increase of 2°C above pre-industrial times could have catastrophic consequences, some of which are shown in the infographic below. Even reducing emissions almost immediately, as seen in the low emissions pathway, will not stop temperatures rising because carbon dioxide lasts in the atmosphere up to a few centuries. Accordingly, to keep the temperature increase below 2°C, total carbon emissions need to remain below 790 Gigatons of carbon (GtC). Putting this into context, 510 GtC were emitted by 2011 and 545 GtC by 2014. So which scenario do you think is the most realistic?

Impacts of different emissions scenarios (World Resources Institute, 2014)

Fortunately, the COP 21 Paris Agreement 2015 has recently come into force. 191 nations signed the legally binding agreement to limit the global temperature increase between pre-industrial times and the year 2100 to “well below 2°C” by 2100, with an aspirational target of 1.5°C.

What is the treatment?

Clearly if all nations immediately become carbon neutral we would meet the climate targets quite comfortably. Problem solved? I don’t think so. The cartoon summarises the issue very well; people don’t want to change that quickly. Yes, the Paris Agreement is an excellent step forward but bearing in mind the global deadline is 2100 a lot can change over that time. Realistically, if I had a deadline due in 84 years I probably wouldn’t put it on the top of my priority list.  

Cartoon climate meeting (The Climate Pioneer, 2010)

The video clip below focuses on meeting the 2°C target. Three and a half minutes into the clip it nicely demonstrates how delaying CO₂ reductions to 2030 would require huge emission cutbacks at a later date to reach the target. Consequently, scientists refer to the need for ‘aggressive policies’ with ‘early and ambitious emission reductions’. These words do not fill me with optimism and I am not alone.

Towards the end of the clip it touches on one of the more controversial solutions to climate change, which has gained more ground with the introduction of the Paris targets; geoengineering. By geoengineering, I am referring to the intentional alteration of global processes, such as reducing the amount of sunlight reaching the earth and taking carbon dioxide out of the atmosphere (Caldeira et al., 2013). I must admit I find the ideas slightly shocking, but I am not entirely dismissive of geoengineering, which I have always considered a space age technology.

Are there any side effects?

Over the next few months I’m going to explore a range of geoengineering technologies to see if they are a viable solution for meeting the climate targets and importantly be answering the last big question. Are there any side effects? Even if geoengineering can reduce the global temperature, is it worth the risks?

Feel free to leave me some comments and questions. Your opinions are welcome here!