"Pay attention to the biosphere-the environment is deteriorating" PPT

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"Pay attention to the biosphere-the environment is deteriorating" PPT

Part One: Import

The natural environment and man-made environment on which human survival depends are both components of the biosphere. Environmental problems caused by human activities are threatening human survival and security. Humans should actively protect the biosphere.

How to effectively control population?

world population day

On July 11, 1987, the world's population reached 5 billion. In order to further encourage governments and people of all countries to pay attention to and solve population issues, the United Nations, in accordance with the recommendations of the 36th session of the UNDP Governing Council, in order to attract the attention of governments and people around the world to population issues, July 11th has been designated as "World Population Day" every year since 1990.

The relationship between late childbearing and population control

Research method: In a specific period of time, through simulation calculation, compare the population increase of early childbearing and late childbearing.

Conditions: Giving birth at the age of 20 is considered early childbearing; giving birth at the age of 25 is considered late childbearing.

Scenario: Two couples A and B, A and their children and grandchildren started having children at the age of 20; B and their children and grandchildren started having children at the age of 25. Calculate the number of generations of their descendants in 100 years.

Result: A and his offspring did not reproduce late, and there will be 5 generations after 100 years; B and his offspring reproduced late, and there will be 4 generations after 100 years. Late childbearing can reduce the population by one generation.

Conclusion: Late childbearing can reduce the rate of population increase and control population size.

Pay attention to the biosphere - the environment is deteriorating PPT, the second part: serious environmental problems

acid rain

ozone hole

greenhouse effect

water pollution

sound polution

Pesticide and chemical fertilizer pollution

domestic waste

Pay attention to the biosphere - the environment is deteriorating PPT, the third part: the impact of land use on the biosphere

At present, among the many ecological and environmental problems in our country, the problem of land desertification is the most serious. There are currently 1.689 million square kilometers of desertified land in the country, accounting for 17.6% of the country's land area, involving nearly a thousand counties (banners) across the country. The expansion rate of land desertification is 2,460 square kilometers per year, which is equivalent to the "disappearance" of a medium-sized county in land area every year.

What are the root causes of land desertification?

Experts have discussed this a lot. According to research, large areas of land desertification in my country are caused by both climate and unreasonable human activities. The "most important reasons" are: rapid population growth, irrational use of land in some areas under the dual pressure of population and economic development, blind reclamation, overgrazing of pastures, indiscriminate deforestation, indiscriminate mining and unreasonable water resources The utilization phenomenon is serious and a large amount of desert vegetation is destroyed, resulting in the continuous expansion of desertified land.

Keywords: Jiangsu Education Edition seventh grade biology PPT courseware for the second volume free download, concern about the deterioration of the biosphere environment PPT download, .PPT format;

For more information about the PPT courseware "Concern about the Deterioration of the Biosphere Environment", please click the "Concern about the Deterioration of the Biosphere Environment" ppt tag.

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Update Time: 2024-09-08

This template belongs to biology courseware Jiangsu Education Edition Seventh Grade Biology Volume 2 industry PPT template

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