To Conclude

Well, it's already my last post - this has come round extremely quickly! I'd like to use this last post to summarise the things I've been talking about, and to reflect on my blogging experience. I hope that the passion I have for this subject has come across over the last few months, and that it hasn't been too disorientating - I know I've thrown a lot of different information at this blog, but this really reflects the diverse nature of hydrological climate change and the effects it has on humans, both directly and indirectly.  Some of the posts have had very individual themes, so I'd like to conclude the messages I've been conveying. 

1. Climate change caused by humans is altering the hydrological cycle as a whole, with a wide variety of effects - increased rainfall, drought, declines in water quality, a less reliable water supply, reductions in the water available in the tropics - just to name the major ones.

2. Hydrological climate change is intrinsically linked to human health and well being, seeing as we all depend on water. These effects range from the physical (e.g. contaminated drinking water), to the economic (e.g. damage from flooding), to the mental (e.g. risk of extreme weather and associated fear).

3. Though we are pretty sure what the main trends are going to be, we must not forget that their is still great uncertainty associated with attempting the model changes to the hydrological cycle and their potential effects - uncertainty is inherent whenever you try to predict something that has not yet happened.

4. This is not a problem to leave for the future - it is already happening. I hope that it is has run through the blog that my personal opinion is that now is the time for action. I am deeply worried that the scientific community refuses to be as vocal as it should about the potential effects of climate change, largely as a result of the uncertainties involved and a strict adherence to the traditions of the scientific method, feeling that we have to always talk about the uncertainties to be truly scientific. I disagree with this approach. I have long been an admirer of the late Stephen Schenider, a climate scientist who worked with the IPCC and recognised how science has to change its approach when communicating climate change:

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but — which means that we must include all the doubts, the caveats, the ifs, ands, and buts. On the other hand, we are not just scientists but human beings as well.

Source

Schneider did not directly work on climate change and the hydrological cycle, but I agree with his words. We cannot expect the world to make decisions if things are perceived as so uncertain - the science has to be expressed in a way that makes sense to the world as a whole, and not just the climate scientists, if anything is to truly change. 

I hope you've enjoyed reading my blog, and that I've presented the science fairly. Writing about hydrological climate science in non academic casual language has been such a joy - science exists to be communicated and this is the way to do it best, despite academic prose having it's place. It is my great hope that I can come back and read this blog in 10 years and feel happy in the progress we have made in understanding and mitigating against the effects hydrological climate change may have on humans. Here's hoping.

A Price to Pay

As the penultimate post, I thought I'd start to round off the blog by talking about the economics of adaption - just how much is it going to cost to adapt human water systems to the changes to the hydrological cycle that will likely occur over the next 50 years? Calculating such global costs for the water sector is clearly not a simple task, and there is no trace of certainty in any numbers that have been produced. However, they are figures that are hopefully indicative of the scale of the changes the world will face.

Kirshen (2007) estimates the global cost (more than 200 countries) of maintaining water services at current levels through to 2030 under a medium emissions scenario to be US$531 billion. The United Nations Framework Convention on Climate Change (2007) suggest a figure US$225 billion s (approximately US$11 billion per year), for the same emissions scenario. These are incredibly large numbers - US$11 billion is the equivalent of China's 2016 GDP, and this is only the annual cost of adapting the water sector to maintain water services until 2030!

Looking forward to the year 2050, Ward et al. (2010) use suggest average annual costs of US$19.7 billion (in a drier projection of climate) and US$14.4 billion (in a wetter projection of climate) to maintain current global water supply and flood protection. These numbers were derived by using a global climate model (GCM) to make climate projections, and estimating costs based on the projections. Once again, big numbers.

Perhaps of special interest in addressing the costs of hydrological climate change is sub-Saharan Africa. This is a region that will be particularly affected by climate change, and is a region of the world where many live in poverty. While they are now outdated, having been succeeded with Sustainable Development Goals (SDGs) for 2030, the 2015 Millennium Development Goals have been used to assess the cost of adoption to hydrological climate change in sub-Saharan Africa. Muller (2007) suggests an annual cost for the adaptation of urban water infrastructure of US$1.1 to 2.7 billion to, with an additional $1.0 to 2.5 billion required to upgrade infrastructure to meet the Millennium Development Goals. Clearly these figures are now approaching 10 years out of date, and do not reflect current development targets nor economic changes since then, but they are still useful. The countries of sub-Saharan Africa are amongst the poorest in the world, and will likely struggle to fund such costs. Given the sensitivity and current state of the region, some amount of aid on behalf of the rest of the world is going to be needed here.

I hope this post helps put the financial scale of hydrological climate change in some sort of context, even if it does just address the adaptation of  water infrastructure and makes no reference to the costs of other hydrological changes. While the numbers are very large, please do take them with a pinch of salt; there is obviously no way to be at all sure what the costs will be, and they are very much just estimates. However, they do make a clear point - this is an expensive issue. Humans die without a reliable supply of clean water, so much expense is will have to be paid. Quite as to who will pay is the question, particularly in the case of the poorer area of the world.