Population growth，economic growth，technology changes in relation to environmental changes──A theoretical modelling analysis of environmental changes

This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in relation to demographic transition and process of industrialization. It concludesthat a major way of improving environmental quality is to intensify pollution decreasing technical factorsand that control of population growth will also reduce the pressure on the environment.

Changes of population growth in Tibet Autonomous Region

The population of the Tibet Autonomous Region which is thinly scattered, is almost entirely Tibetan. The unique high and cold climate, varied and changeable topography and social economic and human environment restrict population mobility in the region. Historically there were little statistic documents and the early data about population scale is poorly reliable. After the peaceful liberation of Tibet in 1951, its population went up continuously, and the growth rate has been higher than the national average level since 1964. The general tendency was that the pattern of population increase had changed within a short period. At first, the death rate was lowered quickly and the natural population increase speed was quickened, then, the death rate was lowered further, and the birth rate began to rise at a quick speed. After 1970, both the death rate and birth rate was generally stable, the level was relatively lower than before, the death rate slowed down at a quicker speed than the birth rate. The natural population increase rate rose extremely slowly, which formed the population development situation of fast but steady increase. The future population development tendency is that, the quick increase tendency characterized by young population will continue for quite a long time, and the pressure of future population increase upon resources environment will become increasingly great. The age structure and sex composition of population in Tibet, rather low since long time ago, became increasingly high upon entering the 1980s, but it was still the lowest one compared to other provinces or regions in China. The main reason is due to the low sex ratio of Tibetan infants and children caused by the low sex ratio of newly born infants and the high death rate of male infants, which will slow down the population increase in a limited way. There are few barren lands appropriate for farming and there exist many restricting factors for cultivation or utilization. With further increase in Tibetan population, it is inevitable that per capita available cultivated land will drop continuously. The problem of food supply in Tibet will still be the main issue in its regional development with the increase of population. It is impossible to support a quickly increasing population with the limited agricultural resources in Tibet. Therefore, the population development direction of Tibet can only be to tighten quantity control and to popularize family planning knowledge among Tibetan people. It is a fundamental strategic policy for the social and economic development in Tibet if family planning can be followed progressively on a voluntary basis.

The effect of the causative algae of large-scale HAB in the East China Sea on egg hatching of Argopecten irradians, and population growth of Brachionus plicatilis and Moina mongolica

The impacts of Prorocentrum donghaiense Lu and Alexandrium catenella Balech, causative species of the large-scale HAB in the East China Sea, were studied under laboratory conditions. According to bloom densities, the effects of monocuhure and mixture of the two species were examined on the egg-hatching success ofArgopecten irradiarts Lamarck, and the population growth of Brachionus plicatilis MUller and Moina mongolica Daday. The results showed that monocuhure of A. catenella had a significant inhibition on the egg hatching success of A. irradians, and the population growth of B. plicatilis and M. mongolica. The median effective densities （ED50） inhibiting the egg hatching success of A. irradhms for 24 h and the population growth of B. plicatilis and M. mongolica for 96 h were 800, 630, and 2 400 cells/cm^3 , respectively. Monoculture of P. dongha/ense has no such inhibitory effect on the egg hatching success of A. irradians; P. donghaiense at lower suitable densities could sustain the population growth of B. plicatilis （ 1 × 10^4 ～ 3 ×10^4 cells/cm^3 ） and M. mongolica （2 × 10^4～5 ×10^4 cells/cm^3 ） ; P. donghaiense at higher densities had significantly adverse effect on the population growth of B. plicatilis （4 × 10^4 ～ 10×10^4 cells/cm^3 ） and M. mongolica （ 10 ×10^4 cells/cm^3）. When the two algae were mixed according to bloom densities, P. donghaiense at suitable densities to some extent could decrease the toxicity of A. catenella to B. plicatilis and M. mongolica. The results indicated that the large-scale HAB in the East China Sea could have adverse effect on zooplankton, and might further influence the marine ecosystem, especially when there was also Alexandrium bloom.

Discussing why population growth is still ignored or denied

Due to a number of factors outlined in this article,the issue of population growth is excluded from the sustainability discussion.In this article,we explore some of the ethical presumptions that underlie the issues linking population growth and sustainability.Critics argue that action to address population creates social and economic segregation,and portray overpopulation concerns as being "anti-poor," "anti-developing country," or even "antihuman." Yet,de-linking demographic factors from sustainability concerns ignores significant global realities and trends,such as the ecological limits of the Earth,the welfare and long-term livelihood of the most vulnerable groups,future prospects of humanity,as well as the ecosystems that support society.

Trends of Population Growth in China:Maximum Number Will Exceed 1.5 Billion

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Population Aging and Control of Population Growth

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The Control of Population Growth Is the Function of the Central Government

Mr.Jiang Zcmin,Gencral-Seerctary of the Cen-tral Committee of the Chincse Communist Party and.Chairman of the People's Republic of China,in a rC-ccnt spcech cm phasized that the family planning pro-gramme should be strictly and effectively im plemented in 1994,a year of crucial importance for promoting re-form and opening and thc drive lowards.modernization.To makc continucd contributions to the sociocconomic development in the country,we must fulfil the plan for controlling population growth..The spcech was delivcred at the anua!National Fo-rum on Family Planning Work convened jointly by the Party's Central Committcc and the Statc Council.

Exploring detailed urban-rural development under intersecting population growth and food production scenarios: Trajectories for China’s most populous agricultural province to 2030

Henan,China,is likely the most populous agricultural province worldwide.It is China’s major grain-producing area,with a continuously increasing population(96 million),which is greater than 93%of countries worldwide.However,this province has been experiencing unprecedented urbanization recently due to national policies and measures,such as a plan to build the capital city of Henan into a national center,resulting in severe conflicts in land use that endanger food security regionally and globally.To facilitate decision-making on this problem,we explored the detailed urban-rural development of Henan by modeling these land-use conflicts.Conventional modeling of a region’s urban-rural development is to navigate trade-offs(a)solely between different land-use types(b)by assuming that each type provides a single service(e.g.,croplands produce all the food),and(c)under a polynomial regression-based projection of population.In contrast,we considered both land-use type and intensity,resulting in a detailed land system for Henan.By introducing the concept of land system services(e.g.,food production),we established a many-to-many relationship between land system classes and services.These allowed us to carry out the most comprehensive modeling of Henan’s urban-rural development under eighteen combined scenarios of population growth and land-use policies on food production.The modeling results of these scenarios provide a solid basis for making decisions regarding Henan’s urban-rural development.We also revealed the influence mechanism of population growth,land-use policies,and their combinations,highlighting the benefits of securing food production by agricultural intensification rather than merely expanding the area of cropland.

Effects of two polybrominated diphenyl ethers(BDE-47,BDE-209) on the swimming behavior, population growth and reproduction of the rotifer Brachionus plicatilis

Polybrominated diphenyl ethers（PBDEs） are new kinds of persistent organic pollutants（POPs） and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE（BDE-47）and deca-BDE（BDE-209） were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that：（1） The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS（Gas Chromatography-Mass Spectrometer） were much lower than their nominal concentrations.（2） In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.（3） Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females（OF/NOF）, the ratio of mictic females/amictic females（MF/AF）, resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.

Comparative Evaluation on Combined Ecotoxic Effects of Nitrofurazone and NH_(4)Cl Using Two Ciliated Protists as Model Organisms:Population Dynamics and Growth Rates

Ecotoxic effects of antibiotics or ammonium have been confirmed independently in aquatic animals,but few studies have investigated their combined effects.In aquaculture ecosystems,these pollutants frequently coexist,and often in high concentrations.In this study,the combined effects of antibiotic nitrofurazone and NH4 Cl on the population dynamics and growth rates of two species of ciliated protists,Euplotes vannus and Pseudokeronopsis rubra,were investigated.Profiles of the dose-responses were visualized,and interactions between the two pollutants were quantified by the response surface method(RSM).Results showed that 1)the dynamics of the population growth differed significantly between the testd ciliates and varied with the concentrations of the pollutants;2)the relative growth rate(RGR)of both ciliates decreased significantly with increased pollutant concentrations,while the difference in RGR between the two ciliates was not significant;3)RSM analysis demonstrated an additive effect of nitrofurazone and NH4 Cl on the RGR in both ciliates.In brief,ecotoxic effects can be caused by nitrofurazone and ammonium independently on the two test ciliates,and such effects can be strengthened when they present at the same time.These findings offer a valuable reference for evaluating combined ecotoxic effects caused by multiple pollutants in aquaculture ecosystems.

Can environmental sustainability be decoupled from economic growth? Empirical evidence from Eastern Europe using the common correlated effect mean group test

The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.

Stability in terms of two measures for population growth models with impulsive perturbations

In this paper,we establish some criteria for the stability of trivial solution of population growth models with impulsive perturbations.The working tools are based on the theory of generalized ordinary differential equations.Here,the conditions concerning the functions are more general than the classical ones.

Water Scarcity in Conakry, Guinea: Challenges and Proposed Strategies for a Way Forward

The capital of Guinea, Conakry, faces a notable difficulty due to a water shortage, which is worsened by the rapid increase in population and urban development. The Guinean Water Company (SEG) faces challenges in supplying water to the entire city due to its limited area of approximately 420 km2 and a population of 2 million. Moreover, the population growth rate is anticipated to increase dramatically, exacerbating the difficulty of fulfilling future water requirements. As a result, this study employs data from the Knoema website and the Institute of National Statistics of Guinea (INS) to examine the water production and distribution process by the SEG. The study examines the challenges related to water scarcity in Conakry and suggests strategies to assist the city in managing the present circumstances and planning for the future. The primary objective is to get a long-lasting water supply and uphold water quality to advance public health.

Global Electricity Demand and Clean Energy Source Growth Scenario

It is impossible to overstate the importance of energy.Just thinking about where humanity would be without it may be enough to demonstrate this point.Like in the past,energy will play a vital role in shaping future industries,cities,nations,and the world.That is why we believe that energy is a critical factor in shaping future paradigms in any target entity or world.To have a better understanding of the role that energy plays in the world today and in the future,in this article,we briefly look at the definition of energy and its different forms,and review some data related to energy consumption in the world and the United States.Furthermore,as a source of clean energy,we believe the future of nuclear power technology,despite the challenges it faces,is an important option for this country and the rest of the world to meet future energy needs without emitting CO(carbon monoxide)and CO2(carbon dioxide),or other GHGs(greenhouse gases),and other atmospheric pollutants and it is more efficient among its other comparable sources of renewable energies,such as solar,wind,etc.Globally,renewables made up 29 percent of electricity generation in 2020,much of it from hydro-power(16.8 percent).A record amount of over 256 GW of renewable power capacity was added globally during 2020 and continues to be the focal point for climate and energy solutions.Demand for electricity is direct function of population growth globally and is also driven by the present century’s extraordinary technological developments.

Investigating the causes of Lake Urmia shrinkage:climate change or anthropogenic factors?

In the current scenario,Lake Urmia,one of the vastest hyper saline lakes on the Earth,has been affected by serious environmental degradation.Using different satellite images and observational data,this study investigated the changes in the lake for the period 1970–2020 based on the effects of climate change and several human-induced processes on Lake Urmia,such as population growth,excessive dam construction,low irrigation water use efficiency,poor water resources management,increased sediment flow into the lake,and lack of political and legal frameworks.The results indicated that between 1970 and 1997,the process of change in Lake Urmia was slow;however;the shrinkage was faster between 1998 and 2018,with about 30.00%of the lake area disappearing.As per the findings,anthropogenic factors had a much greater impact on Lake Urmia than climate change and prolonged drought;the mismanagement of water consumption in the agricultural sector and surface and underground water withdrawals in the basin have resulted in a sharp decrease in the lake's surface.These challenges have serious implications for water resources management in Lake Urmia Basin.Therefore,we provided a comprehensive overview of anthropogenic factors on the changes in Lake Urmia along with existing opportunities for better water resources management in Lake Urmia Basin.This study serves as a guideline framework for climate scientists and hydrologists in order to assess the effects of different factors on lake water resources and for decision-makers to formulate strategies and plans according to the management task.

Lessons Africa Can Learn From China’s Experience in Urbanization

The rapid urbanization of Africa is facing a multitude of challenges.This paper analyzes the seven major issues currently plaguing African urbanization:regional development imbalances,the disconnect between urbanization and economic growth,increasing complexities in the urbanization process,the constraining effect of lagging agriculture,low quality of urbanization,lack of coordination between urbanization and modernization,and excessive population concentration in urban areas.To address these issues,Africa can draw valuable lessons from other countries,particularly from China’s experience in urban development.Since 1978,China has seen a rapid increase in its urbanization rate.The key to this success lies in policy orientation,labor force transition,prioritized regional development,and attracting foreign investment among other strategies.By learning from China’s experience,African countries can optimize agricultural modernization,strengthen the manufacturing sector,increase investment in infrastructure,and accelerate the process of digitization,thereby creating new opportunities for their urbanization process.This paper explores the rapidly developing urbanization process in Africa and the accompanying challenges.It also analyzes China’s experience in urbanization,offering insights and recommendations for Africa’s urban development.