Editing IPCC:AR6/SR15/Chapter-2 (section)

== FAQ 2.2 What do Energy Supply and Demand have to do with Limiting Warming to 1.5°C? ==

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'''''Summary''''' '': Limiting global warming to 1.5°C above pre-industrial levels would require major reductions in greenhouse gas emissions in all sectors. But different sectors are not independent of each other, and making changes in one can have implications for another. For example, if we as a society use a lot of energy, then this could mean we have less flexibility in the choice of mitigation options available to limit warming to 1.5°C. If we use less energy, the choice of possible actions is greater – for example, we could be less reliant on technologies that remove carbon dioxide ('' CO <sub>2</sub> )  ''from the atmosphere.''

To stabilize global temperature at any level, ‘net’ CO <sub>2</sub>  emissions would need to be reduced to zero. This means the amount of CO <sub>2</sub>  entering the atmosphere must equal the amount that is removed. Achieving a balance between CO <sub>2</sub>  ‘sources’ and ‘sinks’ is often referred to as ‘net zero’ emissions or ‘carbon neutrality’. The implication of net zero emissions is that the concentration of CO <sub>2 </sub> in the atmosphere would slowly decline over time until a new equilibrium is reached, as CO <sub>2</sub>  emissions from human activity are redistributed and taken up by the oceans and the land biosphere. This would lead to a near-constant global temperature over many centuries.

Warming will not be limited to 1.5°C or 2°C unless transformations in a number of areas achieve the required greenhouse gas emissions reductions. Emissions would need to decline rapidly across all of society’s main sectors, including buildings, industry, transport, energy, and agriculture, forestry and other land use (AFOLU). Actions that can reduce emissions include, for example, phasing out coal in the energy sector, increasing the amount of energy produced from renewable sources, electrifying transport, and reducing the ‘carbon footprint’ of the food we consume.

The above are examples of ‘supply-side’ actions. Broadly speaking, these are actions that can reduce greenhouse gas emissions through the use of low-carbon solutions. A different type of action can reduce how much energy human society uses, while still ensuring increasing levels of development and well-being. Known as ‘demand-side’ actions, this category includes improving energy efficiency in buildings and reducing consumption of energy- and greenhouse-gas intensive products through behavioural and lifestyle changes, for example. Demand- and supply-side measures are not an either-or question, they work in parallel with each other. But emphasis can be given to one or the other.

Making changes in one sector can have consequences for another, as they are not independent of each other. In other words, the choices that we make now as a society in one sector can either restrict or expand our options later on. For example, a high demand for energy could mean we would need to deploy almost all known options to reduce emissions in order to limit global temperature rise to 1.5°C above pre-industrial levels, with the potential for adverse side-effects. In particular, a pathway with high energy demand would increase our reliance on practices and technologies that remove CO <sub>2</sub>  from the atmosphere. As of yet, such techniques have not been proven to work on a large scale and, depending on how they are implemented, could compete for land and water. By leading to lower overall energy demand, effective demand-side measures could allow for greater flexibility in how we structure our energy system. However, demand-side measures are not easy to implement and barriers have prevented the most efficient practices being used in the past.

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'''FAQ 2.2 Figure 1'''

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'''Having a lower energy demand increases the flexibility in choosing options for supplying energy.'''
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[[File:e58e48daf43222383c90669320c08856 FAQ-2.2-1024x548.jpg]]

A larger energy demand means many more low carbon energy supply options would need to be used.

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