Wow – what a scorcher of a summer we’ve been having in the UK! And we haven’t been alone in experiencing very high temperatures and very low rainfall for a prolonged period. Records have been broken in many places across the northern hemisphere – from the usually mild SE Canada to the sweltering Oman in the Middle East, from Portugal to Armenia – with ‘heat domes’ apparently immovably settled over large land areas. Even the Arctic was not immune with temperatures earlier this year more than 20°C above their usual levels. Sadly, such weather events have had many unfortunate consequences on lives, ecosystems, property and livelihoods. I don’t think that Beatle George Harrison had such extreme hot weather in mind when he penned the whimsical lyrics of ‘Here Comes the Sun’ in 1969!
Now, I’m well aware of the difference between weather and climate, and I know that no single temperature record broken, in isolation, can be attributed to climate change. However, I firmly believe that collectively, the weather we have experienced in recent years and around the world is showing a clear trend that is consistent with the kind of climate changes we can expect in a warming world.
Keeping global warming to within 1.5-2°C may be more difficult than we thought
In this contxt, I wasn’t surprised to hear, last week, about the findings of a study published in Proceedings of the National Academy of Sciences (PNAS) by an international team of scientists showing that even if the carbon emission reductions called for in the Paris Agreement are met, there is a risk of our planet entering what the scientists call “Hothouse Earth” conditions (i.e. stabilised at a global average of 4-5°C higher than pre-industrial temperatures, and with sea level 10-60m higher than today). Why? The study suggests that human-induced global warming of 2°C – the figure that the Paris Agreement aims to limit the global average warming to – may trigger other Earth system processes, often referred to as ‘feedback loops’, that could drive further warming, even if we were to completely stop emitting greenhouse gases. The authors of the study consider ten natural feedback processes, some of which they consider to be “tipping elements” that lead to abrupt change if a critical threshold is crossed. These feedback processes are: permafrost thaw, loss of methane hydrates on the ocean floor, weakening land and ocean carbon sinks, increasing bacterial respiration in the oceans, Amazon rainforest dieback, boreal forest dieback, reduction of northern hemisphere snow cover, loss of Arctic summer sea ice, and reduction of Antarctic sea ice and polar ice sheets. Such tipping elements could potentially act like a row of dominoes – once one tips, it pushes earth towards another. “Places on Earth will become uninhabitable if ‘Hothouse Earth’ becomes a reality”, warns co-author Johan Rockström, former executive director of the Stockholm Resilience Centre and incoming co-director of the Potsdam Institute for Climate Impact Research.
Cutting greenhouse gases is not enough
Maximising the chances of avoiding a “Hothouse Earth” requires not only reduction of carbon dioxide and other greenhouse gas emissions but also “enhancement and/or creation of new biological carbon stores, for example, through improved forest, agricultural and soil management; biodiversity conservation; and technologies that remove carbon dioxide from the atmosphere and store it underground” the paper states. Critically, the study emphasises that such measures must be underpinned by fundamental societal changes that are required to maintain a “stabilised Earth” where temperatures are no more than 2°C warmer than pre-industrial temperatures.
Clearly, there is a need for concerted urgent action, and IFRF and its members should be fully engaged in this. One key challenge we are certainly directly engaged with is decarbonising energy systems.
Is full decarbonisation of energy systems feasible?
Many countries around the world are making good progress towards decarbonising their electricity systems, but since electricity represents only about one third of total energy worldwide, we must now focus our attentions on decarbonisation of the heat and transport sectors if we are to move towards full decarbonisation of energy systems (considered vital if we are to meet the carbon reduction targets mandated by climate change across the whole of society). But is total energy decarbonisation even possible?
This challenging question reminds me of a recently published report from Helsinki-based consulting group Pöyry (which I rate highly) – ‘Fully Decarbonising Europe’s Energy System by 2050’. This excellent report, published in May this year, asserts that Europe’s whole energy system could be fully decarbonised by 2050. How?
Pöyry differentiates two distinct pathways – the first via “full electrification” (in which both the heat and transport sectors are fully electrified, with the electricity supplied by zero-carbon electricity generation technologies); the other via “zero-carbon gas” (in which biomethane, hydrogen and natural gas with carbon capture and storage (CCS) play a significant role). Pöyry concludes that the latter pathway is the cheaper and more flexible solution, as excluding non-electric technical options would necessitate investing in significant new nuclear generation capacity.
In the zero-carbon gas pathway, the above mix of gases would source the energy required for heating and parts of the transport sector (e.g. heavy duty vehicles where hydrogen fuel cells are more efficient than batteries).
Of course, fully decarbonising Europe’s energy system by 2050 will require a massive investment – almost £1 trillion on new power generation plant alone (and more if the full electrification pathway is adopted). Clearly, major growth of renewable energy sources (mainly solar PV and wind energy) is critical to decarbonising the electricity system, and Pöyry says that the growth of smart electricity networks and demand response solutions will largely address issues of intermittent generation of these renewable sources.
Pöyry is, in effect, arguing that “new gas vectors” (i.e. natural gas with CCS and some zero-carbon gases) can maintain long-term roles in a decarbonised energy system. This argument differs from the US Electric Power Research Institute’s (EPRI) ‘Integrated Energy Network’ concept (see MNM piece on 7th August 2017), which focuses on electrification and efficiency as the preferred pathway to fully decarbonised energy, with gas tolerated only temporarily as a transition fuel.
From an IFRF perspective, both pathways are of considerable interest in terms of research and development requirements. Technologies including biomass combustion/gasification, bio-energy with CCS (‘BECCS’) are highly relevant in the full electrification pathway, with production of biomethane (e.g. from anaerobic digestion processes), combustion of biomethane and hydrogen in industrial processes, and CCS on natural gas combustion systems relevant in the zero-carbon gas pathway.
Whichever pathway is followed, full decarbonisation of Europe’s whole energy system would be a huge and expensive undertaking, providing an urgent challenge to all those organisations involved in the ‘coupled’ sectors of electricity generation, heat generation and transport.