This paper presents the Regional Integrated model of Climate and the Economy (RICE), a dynamic general-equilibrium model that analyzes different national strategies for climate change policy. The RICE model disaggregates the global economy into regions and considers various strategies: market solutions, cooperative outcomes, and noncooperative equilibria. The study finds that cooperative policies lead to significantly higher emissions reductions than noncooperative strategies. It also highlights substantial differences in control levels among countries in both cooperative and noncooperative policies, and notes that high-income countries may be major losers from cooperation. The paper discusses the complexity of climate change, which involves multiple systems, including the carbon cycle, climate reactions, and economic impacts. It emphasizes the high stakes of climate change, with potential global temperature increases of around 3°C over the next century, leading to unprecedented climate conditions. The costs of slowing climate change are also significant, with even stringent policies costing hundreds of billions annually. The RICE model integrates climate-related sectors with the economic model, incorporating geophysical relationships, emissions equations, and climate-damage relationships. It distinguishes three strategies: market policies, cooperative policies, and noncooperative policies. The model divides the global economy into 10 regions, with different numbers of countries in each region. It calculates the net benefits of emissions for each region and considers the free-riding tendencies of global public goods. The RICE model uses a Negishi solution to find the cooperative equilibrium, which involves maximizing a social welfare function with adjusted welfare weights. The model also calculates the noncooperative equilibrium using a Nash equilibrium approach, where each country maximizes its own economic welfare. The results show that cooperative policies lead to higher emissions reductions and lower temperatures compared to noncooperative strategies. However, high-income countries may be major losers from cooperation. The paper also discusses the economic and environmental impacts of alternative strategies, showing that the RICE model projects higher world output and emissions than other models. It highlights the distribution of control rates and carbon taxes across regions, with high-income countries having higher control rates and carbon taxes. The study concludes that the cooperative solution may not emerge as the outcome of a bargaining process if it does not improve the economic welfare of all countries. The results indicate that the cooperative solution may reduce the standards of living of major regions for at least half a century and reduce the discounted net welfare of the United States when all time periods are considered.This paper presents the Regional Integrated model of Climate and the Economy (RICE), a dynamic general-equilibrium model that analyzes different national strategies for climate change policy. The RICE model disaggregates the global economy into regions and considers various strategies: market solutions, cooperative outcomes, and noncooperative equilibria. The study finds that cooperative policies lead to significantly higher emissions reductions than noncooperative strategies. It also highlights substantial differences in control levels among countries in both cooperative and noncooperative policies, and notes that high-income countries may be major losers from cooperation. The paper discusses the complexity of climate change, which involves multiple systems, including the carbon cycle, climate reactions, and economic impacts. It emphasizes the high stakes of climate change, with potential global temperature increases of around 3°C over the next century, leading to unprecedented climate conditions. The costs of slowing climate change are also significant, with even stringent policies costing hundreds of billions annually. The RICE model integrates climate-related sectors with the economic model, incorporating geophysical relationships, emissions equations, and climate-damage relationships. It distinguishes three strategies: market policies, cooperative policies, and noncooperative policies. The model divides the global economy into 10 regions, with different numbers of countries in each region. It calculates the net benefits of emissions for each region and considers the free-riding tendencies of global public goods. The RICE model uses a Negishi solution to find the cooperative equilibrium, which involves maximizing a social welfare function with adjusted welfare weights. The model also calculates the noncooperative equilibrium using a Nash equilibrium approach, where each country maximizes its own economic welfare. The results show that cooperative policies lead to higher emissions reductions and lower temperatures compared to noncooperative strategies. However, high-income countries may be major losers from cooperation. The paper also discusses the economic and environmental impacts of alternative strategies, showing that the RICE model projects higher world output and emissions than other models. It highlights the distribution of control rates and carbon taxes across regions, with high-income countries having higher control rates and carbon taxes. The study concludes that the cooperative solution may not emerge as the outcome of a bargaining process if it does not improve the economic welfare of all countries. The results indicate that the cooperative solution may reduce the standards of living of major regions for at least half a century and reduce the discounted net welfare of the United States when all time periods are considered.