IEA提唱のNet Zero by 2050の中身の概要

2050年までにCO2排出ゼロを世界的目標に定めましたが、その大元のレポートはIEAのまとめた"Net Zero by 2050 / A Roadmap for the Global Energy Sector"というものです。その概要を簡単に紹介させて頂きます。

国際エネルギー機関（International Energy Agency：IEA）は、29の加盟国が、その国民に信頼できる、安価でクリーンなエネルギーを提供する為の諮問機関。当初1973年の第1次石油危機を契機に、アメリカのキッシンジャー国務長官の提唱のもと、1974年に加盟国の石油供給危機回避（安定したエネルギー需給構造を確立すること）を目的に設立された。やがて、エネルギー市場の変化に伴いその役割も変化した。現在は「スリーE：バランスの取れたエネルギー政策立案、エネルギー安全保障、経済発展と環境保護」を掲げており、焦点は、気候変動に関する政策と市場改革、再生可能エネルギー技術開発におけるコラボレーションと加盟外国々へのアウトリーチ（特にエネルギー大国である中国、インド、ロシアそしてOPEC加盟国）である。2009年には意見の対立から国際再生可能エネルギー機関が生まれたが、現在は協力関係にある。

Net Zero by 2050 / A Roadmap for the Global Energy Sector

Source: IEA (International Energy Agency). All rights reserved.
Website: www.iea.org

A global pathway to net-zero CO₂ emissions in 2050

The Net‐Zero Emissions by 2050 Scenario (NZE) shows what is needed for the global energy sector to achieve net‐zero CO2 emissions by 2050. Alongside corresponding reductions in GHG (greenhouse gas) emissions from outside the energy sector, this is consistent with limiting the global temperature rise to 1.5 °C without a temperature overshoot (with a 50% probability). Achieving this would require all governments to increase ambitions from current Nationally Determined Contributions and net zero pledges.

In the NZE (Net‐Zero Emissions), global energy‐related and industrial process CO2 emissions fall by nearly 40% between 2020 and 2030 and to net zero in 2050. Universal access to sustainable energy is achieved by 2030. There is a 75% reduction in methane emissions from fossil fuel use by 2030. These changes take place while the global economy more than doubles through to 2050 and the global population increases by 2 billion.

Total energy supply falls by 7% between 2020 and 2030 in the NZE and remains at around this level to 2050. Solar PV (photovoltaics) and wind become the leading sources of electricity globally before 2030 and together they provide nearly 70% of global generation in 2050. The traditional use of bioenergy is phased out by 2030.

Coal demand declines by 90% to less than 600 Mtce (Mega Tonnes of Coal Equivalent) in 2050, oil declines by 75% to 24 mb/d (million barrels per day), and natural gas declines by 55% to 1750 bcm (billion cubic metres). The fossil fuels that remain in 2050 are used in the production of non‐energy goods where the carbon is embodied in the product (like plastics), in plants with carbon capture, utilisation and storage (CCUS/Carbon Capture, Usage and Storage技術は、産業活動から排出される高濃度のCO₂を固定化し、または有効に利用する技術), and in sectors where low‐emissions technology options are scarce.

Energy efficiency, wind and solar provide around half of emissions savings to 2030 in the NZE. They continue to deliver emissions reductions beyond 2030, but the period to 2050 sees increasing electrification, hydrogen use and CCUS deployment, for which not all technologies are available on the market today, and these provide more than half of emissions savings between 2030 and 2050. In 2050, there is 1.9 Gt (gigatonnes) of CO2 removal in the NZE and 520 million tonnes of low‐carbon hydrogen demand.

Behavioural changes by citizens and businesses avoid 1.7 Gt CO2 emissions in 2030, curb energy demand growth, and facilitate clean energy transitions.

Annual energy sector investment, which averaged USD 2.3 trillion globally in recent years, jumps to USD 5 trillion by 2030 in the NZE. As a share of global GDP, average annual energy investment to 2050 in the NZE is around 1% higher than in recent years.

The NZE taps into all opportunities to decarbonise the energy sector, across all fuels and all technologies. But the path to 2050 has many uncertainties. If behavioural changes were to be more limited than envisaged in the NZE, or sustainable bioenergy less available, then the energy transition would be more expensive. A failure to develop CCUS for fossil fuels could delay or prevent the development of CCUS for process emissions from cement production and carbon removal technologies, making it much harder to achieve net‐zero emissions by 2050.

Wider implications of achieving net-zero emissions

Economy: In our Net‐Zero Emissions by 2050 Scenario (NZE), global CO2 emissions reach net zero by 2050 and investment rises across electricity, low‐emissions fuels, infrastructure and end‐use sectors. Clean energy employment increases by 14 million to 2030, but employment in oil, gas and coal declines by around 5 million. There are varying results for different regions, with job gains not always occurring in the same place, or matching the same skill set, as job losses. The increase in jobs and investment stimulates economic output, resulting in a net increase in global GDP to 2030. But oil and gas revenues in producer economies are 80% lower in 2050 than in recent years and tax revenues from retail oil and gas sales in importing countries are 90% lower.

Energy industry: There is a major contraction in fossil fuel production, but companies that produce these fuels have skills and resources that could play a key role in developing new low‐emissions fuels and technologies. The electricity industry scales up to meet demand rising over two‐and‐a‐half‐fold to 2050 and becomes more capital intensive, focusing on renewables, sources of flexibility and grids. Large energyconsuming companies, vehicle manufacturers and their suppliers adjust designs and retool factories while improving efficiency and switching to alternative fuel supplies.

For citizens who lack access to electricity and clean cooking, the NZE delivers universal access by 2030. This costs around USD 40 billion a year over the next decade and adds less than 0.2% to CO2 emissions. For citizens the world over, the NZE brings profound changes, and their active support is essential if it is to succeed. Around three‐quarters of behavioural changes in the NZE can be directly influenced or mandated by government policies. The cost of energy is also an important issue for citizens, and the proportion of disposable household income spent on energy over the period to 2050 remains stable in emerging market and developing economies, despite a large increase in demand for modern energy services.

Government action is central to achieve net‐zero emissions globally by 2050; it underpins the decisions made by all other actors. Four particular points are worth stressing. First, the NZE depends on actions that go far beyond the remit of energy ministers, and requires a co‐ordinated cross‐government approach. Second, the fall in oil and gas demand in the NZE may reduce some traditional energy security risks, but they do not disappear, while potential new vulnerabilities emerge from increasing reliance on electricity systems and critical minerals. Third, accelerated innovation is needed. The emissions cuts to 2030 in the NZE can be mostly achieved with technologies on the market today, but almost half of the reductions in 2050 depend on technologies that are currently under development. Fourth, an unprecedented level of international co‐operation is needed. This helps to accelerate innovation, develop international standards and facilitate new infrastructure to link national markets. Without the co‐operation assumed in the NZE, the transition to net‐zero emissions would be delayed by decades.

There are multiple milestones on the way to global net-zero emissions by 2050. If any sector lags, it may prove impossible to make up the difference elsewhere.

Net Zero by 2050を達成するには、地球上の全ての国々の強力なcommitmentが必要ですが、各国のenergy事情やCO2排出削減に対する意識の強弱があり、また、CO2排出ゼロを達成するためには莫大な投資が必要となりますが、コロナ下で世界中の国の財政基盤が脆弱になった今、達成へのハードルは非常に高いのが現実だと思います。しかし、未来の地球上で暮らす人々にとって、Net Zero by 2050という目標は、豊かで安全に暮らすための必要必達条件であり、この目標達成に向けて、全世界が一致団結できれば、新たな共生的国際関係が醸成されるチャンスとなるかもしれません。