As of last update in September 2021, there was no specific global agreement that mandated which countries would "foot the bill" for addressing climate change. The responsibility for funding climate change mitigation and adaptation efforts has been a complex and contentious issue in international climate negotiations.

Historically, developed countries have been major contributors to greenhouse gas emissions, and they are often expected to take the lead in funding climate change initiatives. This principle of "common but differentiated responsibilities" is enshrined in the United Nations Framework Convention on Climate Change (UNFCCC).

Several mechanisms have been established to help finance climate-related projects and support developing countries' efforts to tackle climate change. Some of these include:

1. Green Climate Fund (GCF): The GCF was established as a financial mechanism under the UNFCCC to assist developing countries in adaptation and mitigation practices. It aims to allocate resources to projects and programs that contribute to climate change solutions.

2. Global Environment Facility (GEF): The GEF provides grants and concessional funding for projects in developing countries related to biodiversity, climate change, international waters, land degradation, and chemicals.

3. Climate finance from developed countries: Many developed nations pledge bilateral and multilateral climate finance commitments to help developing countries transition to low-carbon economies and build resilience against climate change impacts.

4. Private sector investments: The private sector also plays a crucial role in financing climate-related projects and initiatives, including renewable energy infrastructure, energy efficiency programs, and sustainable development projects.

It's important to note that the landscape of climate finance is continuously evolving, and there may be new developments beyond my last update. As of that time, countries were still negotiating and discussing the financial aspects of climate change mitigation and adaptation, with ongoing debates over the adequacy of funding and the equitable distribution of responsibilities.

For the most up-to-date information on this topic, I recommend referring to recent reports and updates from reputable sources such as the United Nations, the Intergovernmental Panel on Climate Change (IPCC), and other international climate organizations.

Why is countries like China, Saudi Arabia, Brazil and all oil producing countries not paid up?

As of last update in September 2021, countries like China, Saudi Arabia, Brazil, and other oil-producing nations were not explicitly "paid up" in the context of climate change. It's essential to clarify that there is no direct payment made by specific countries to address climate change, but rather a collective effort to finance climate-related initiatives.

The issue of climate finance and contributions from different countries has been a contentious and complex topic in international climate negotiations. Here are some reasons why certain countries, including China, Saudi Arabia, Brazil, and oil-producing nations, may face scrutiny or challenges in their climate change commitments:

1. Historic emissions: Developed countries, particularly those in the Global North, have historically been responsible for the majority of greenhouse gas emissions. As a result, they are often expected to take greater responsibility and provide financial support to help developing countries transition to sustainable practices and adapt to the impacts of climate change.

2. Development priorities: Developing countries, including some oil-producing nations, may argue that their primary focus is on economic development and poverty alleviation. They might believe that imposing stringent emission reduction targets could hinder their economic growth.

3. Differentiated responsibilities: The principle of "common but differentiated responsibilities" within the UNFCCC recognizes that developed and developing countries have different levels of historical responsibility for climate change. Developing countries often emphasize that industrialized nations should bear the bulk of the financial burden.

4. Political and economic interests: Countries with substantial fossil fuel reserves may have economic and political interests in maintaining their fossil fuel industries. Transitioning away from fossil fuels could have significant economic implications, and these countries may resist changes that could affect their energy sectors.

5. Climate action progress: Some countries, like China and Brazil, have made significant strides in recent years in investing in renewable energy and taking action to reduce emissions. However, there are still concerns about the scale and pace of their efforts, especially given their large populations and economies.

6. Access to climate finance: Access to climate finance for developing countries can be challenging due to bureaucratic processes, lack of capacity, or difficulties in attracting private sector investment.

It's important to note that climate negotiations and international agreements are complex and ongoing processes. Countries continue to engage in discussions, debates, and commitments to address climate change collectively. Since my information is up to September 2021, I recommend seeking updated sources to understand the current status of climate change negotiations and the contributions made by different countries as the situation may have evolved since then.

Why is China in particular keep consuming and building more coal powerhouse?

As of last update in September 2021, China's reliance on coal for energy production was a significant concern in the context of global efforts to combat climate change. While China has been investing heavily in renewable energy sources, it has also continued to build and operate coal-fired power plants for several reasons:

1. Energy demand and economic growth: China is the world's most populous country and has experienced rapid economic growth over the past few decades. Meeting the energy demands of such a large and growing economy has been a priority, and coal has been a cheap and abundant energy source for China.

2. Energy security: Coal reserves in China are extensive, and the country has sought to use its domestic resources to enhance energy security and reduce dependence on imported fuels.

3. Job creation and local economies: Coal mining and related industries have been significant employers in certain regions of China. The construction and operation of coal-fired power plants can create jobs and support local economies, which could be a factor in the government's decision-making.

4. Industrial capacity and infrastructure: China's extensive coal-based energy infrastructure, including power plants and transportation systems, has been deeply ingrained in the country's energy mix. Transitioning away from coal would require substantial investments and may take time.

5. Grid stability and baseload power: Coal-fired power plants provide a stable and consistent baseload power supply, which is crucial for maintaining the stability of the electricity grid, particularly as renewable energy sources like solar and wind can be intermittent.

Despite these factors, it's important to note that China has also taken significant steps to address its coal consumption and carbon emissions:

1. Renewable energy investments: China has become a global leader in renewable energy investment and deployment, particularly in solar and wind power. The country has been rapidly expanding its capacity for renewable energy generation.

2. Climate commitments: China has made commitments to peak its carbon emissions before 2030 and achieve carbon neutrality by 2060. This suggests a willingness to transition away from coal in the long term.

3. Environmental concerns: China has faced increasing pressure from its citizens and the international community to address air pollution and environmental degradation associated with coal use. As a result, the Chinese government has taken measures to improve air quality and reduce the most polluting coal-fired power plants.

4. Green finance initiatives: China has been promoting green finance and sustainable investments to support the transition to a low-carbon economy.

It's worth mentioning that the situation is continually evolving, and China's energy policies and strategies may have changed since my last update in 2021. For the latest information on China's energy and climate policies, it is recommended to refer to up-to-date sources and official statements from the Chinese government and reputable international organizations.