The expected ratio of investment in clean energy compared to fossil fuels in 2030, according to the IEA's report, is 5:1 in favor of clean energy. This means that for every dollar invested in fossil fuels, five dollars will be invested in clean energy.

Reasons for the expected ratio of investment in clean energy compared to fossil fuels in 2030:

1. Transition to a low-carbon economy: The global focus on reducing greenhouse gas emissions and combating climate change has led to an increased emphasis on clean energy sources. Governments, organizations, and investors are recognizing the need to transition away from fossil fuels towards renewable and sustainable energy sources.

2. Falling costs of clean energy technologies: Over the years, the costs of renewable energy technologies such as solar and wind power have significantly declined. This has made clean energy more competitive and attractive to investors. As a result, there is a growing trend of shifting investment towards clean energy projects.

3. Policy support and incentives: Many countries have implemented policies and incentives to promote clean energy investment. These include feed-in tariffs, tax credits, renewable portfolio standards, and carbon pricing mechanisms. Such policies create a favorable environment for clean energy investment and encourage the shift away from fossil fuels.

4. Growing public demand and awareness: There is an increasing awareness among the public about the environmental impacts of fossil fuels and the benefits of clean energy. This has led to a rising demand for renewable energy and a shift in consumer preferences. Investors are responding to this demand by allocating more funds towards clean energy projects.

5. Long-term sustainability and resilience: Clean energy sources such as solar, wind, and hydroelectric power offer long-term sustainability and resilience compared to fossil fuels, which are finite resources. Investors recognize the potential for long-term returns and stability in clean energy investments.

Conclusion:
The expected ratio of investment in clean energy compared to fossil fuels in 2030 is 5:1 in favor of clean energy. This reflects the global shift towards renewable and sustainable energy sources driven by factors such as falling costs, policy support, public demand, and long-term sustainability.

The World Energy Outlook 2023 report indicates that global investment in clean energy is expected to be nearly five times that of fossil fuels by the year 2030. This trend reflects the world's shift towards sustainable and eco-friendly energy solutions.