Читать книгу Renewable Energy - David Elliott - Страница 17

In terms of what the various energy sources are used for, put very simply, although it varies significantly around the world, the total primary energy that is used for (electric) power generation, for heating and for transport is very roughly split in equal amounts amongst these three end uses, but that pattern is changing with, in some cases, transport taking more.

In terms of carbon dioxide gas emissions from fossil fuel use, total emissions from direct energy production/use have stabilized globally in recent years but rose slightly (by 1.7%) in 2018. Although it varies round the world, there are, very roughly, equal proportions of global greenhouse gas emissions from energy generation (heat and power), transport, industry and agriculture (IEA 2019a). The historical record of emissions illustrates how emissions rose as countries industrialized, led initially by the United Kingdom and then the United States but with China now in the lead (GCP 2020).

For details of energy use and some of the resultant impacts, the UK situation is reported in the annual Digest of UK Energy Statistics (DUKES 2019), the Energy Information Administration produces data on the US situation (EIA 2019), while BP publishes annual global energy outlooks (BP 2019), as does the IEA (IEA 2019a). The IEA’s latest data suggest that global emissions have stabilized again, in part due to reductions in coal use in the United States and the EU (IEA 2020).

The precise extent and timing of the likely social and environmental impacts from the combustion of fossil fuel may still be the subject of some debate, but few doubt that they will continue to grow and cause serious and worsening problems unless major changes are made. Indeed, some fear that, otherwise, the outcome could be catastrophic. Whatever we now do to slow emissions, the impacts from past emissions will have to be faced, in some cases as a matter of urgency. We can also try to adapt in advance to climate change to some extent via ameliorative measures, such as enhanced sea-rise protection in flood-prone areas.

However, if nothing is done to halt or reduce emissions, the impacts will get worse, making adaptation progressively harder, more expensive and in the end futile. It is the same for carbon dioxide removal from the atmosphere: at best, it can deal with some old emissions but more likely, as with post-combustion carbon capture and storage of CO₂ from power plants, it may just be used to compensate for continued fossil fuel use. Carbon capture nevertheless might reduce the associated climate impacts, although there will be limits to the storage space for CO₂. As with adaptation, it is not a long-term answer to climate change and the impacts of continued fossil fuel use. Avoiding emissions at source is a more fundamental, effective and sustainable approach (Schumacher 2019a).

My aim in this book is to ask, how far can the use of renewable energy sources allow us to move in that direction? Can they help us to cut emissions substantially or even entirely, and, if so, when and at what cost?