Final answer:
Stopping deforestation and burning less fossil fuels are key steps to slow down global climate change. Forests absorb CO2, while reducing fossil fuel use cuts greenhouse gas emissions.
Step-by-step explanation:
Choosing two important steps in slowing down global climate change, the most effective would be B) Stopping deforestation and B) Burning less fossil fuels. Stopping deforestation is crucial because forests act as carbon sinks, absorbing CO2 from the atmosphere. By preserving and expanding forests, we can enhance this natural climate regulation. Burning less fossil fuels is essential because burning oil, coal, and gas releases significant amounts of CO2. Transitioning to clean energy sources like solar and wind reduces our dependency on fossil fuels, thereby reducing greenhouse gas emissions. These steps, among others, can contribute to mitigating the effects of climate change.