1)What are the steps to finish global-warming, food-deficiency and water-scarcity alarming issues in coming future?

2)What does macroeconomics do?

3)Did Keynes's experience in investment influence his ideas of macroeconomics?

1)Steps to finish global warming, food deficiency, and water scarcity alarming issues shortly by:

1 Stoping high deforestation and implementing afforestation will improve the quality of the environment leading to better living conditions. Less construction of building in areas of high forest will help in protecting humans from global warming.

2 Water scarcity can best be reduced by applying strict rules on wastage of water and also the government should have punishments during such wastage.

3. Corruption in the country should be reduced to zero so that it helps to distribute the money in the economy more equally than in the corrupted economy as corruptions lead to more in the hands of the rich than the poor.

4. Fiscal and monetary policy in the economy should be strict to improve the deficiency of goods in the economy as strict laws applied will improve the country to a better stage of high efficiency and productivity.

2)Macroeconomics tries to analyze the aggregate economy. The aggregate analysis involves an analysis of the level of inflation in an economy, the unemployment rate in a country and the level of inflation that is being experienced in an economy. Once these aggregate analyses are determined, proper policies are put in place to drive the economy to the desired point.

3)Keynes shows that when the investment is more than saving, it leads to the inflationary situation in the economy. When saving becomes more than the investment, it leads to the recession. The idea of Keynes of the total expenditure of the government and its impact on the production and prices of goods also applies to investment. When the government spends more on growth then it leads to an increase in the private sector to invest more.

When a firm invests in physical assets and intangible assets, they take into account all the expected benefits of the investment.

Keynes's other ideas of investment also influence the unemployment level of an economy. It is because when investment in projects such as education and infrastructure is encouraged by the government, it affects the employment rate by providing opportunities to work.