Question

under the kyoto protocol, developed countries took on a bigger share of limits, which led to
positive changes in the pollution levels worldwide.
increases in the participation of developing countries.
china becoming the leading producer of carbon dioxide emissions.
canada becoming the world leader in its lowered levels of pollution.

Explanation:

The Kyoto Protocol aimed to reduce greenhouse gas emissions. Developed countries having more limits meant that developing countries could have relatively more leeway in emissions in the short - term. As a result, China, a large developing country at the time of the Kyoto Protocol's implementation (1997 - 2012), saw an increase in its industrial production (which often involves carbon - dioxide - emitting processes) and became the leading producer of carbon dioxide emissions during this period.
The Kyoto Protocol did not lead to significant positive changes in worldwide pollution levels as a whole (many countries did not meet their targets). There was no significant increase in the participation of developing countries in terms of taking on more emission - reduction burdens under the Kyoto Protocol's structure (which was based on historical responsibility, giving developing countries more flexibility). Canada did not become a world leader in lowered pollution levels; in fact, Canada withdrew from the Kyoto Protocol in 2012.

Answer:

China becoming the leading producer of carbon dioxide emissions.