Climate change due to the increase in the greenhouse effect (anthropogenic greenhouse effect) caused by the increase in greenhouse gas (GHG) emissions into the atmosphere, especially CO2, is one of the main problems facing humanity. 
In November 2021, the 26th edition of the United Nations Climate Change Conference (called COP26) was held in Glasgow, the aim of which is for the participating countries to discuss and make decisions to reduce emissions.

And mind you, back in 1879, the American engineer and inventor Mary Walton, a pioneer in the defense of the environment, patented a method to reduce the environmental impact of the fumes of unstoppable industrialization. Little did we learn from her 
 
a.- What human activities contribute to increase greenhouse gas emissions? 
b.- How could we reduce CO2 emissions into the atmosphere?