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It has been estimated that industrial fertilizers have increased the planet’s human carrying capacity by two billion people. Unfortunately, most of the chemical fertilizer applied to soils does not nourish the crop as intended, but rather enters the hydrological system, polluting aquifers, streams, and ultimately the oceans with an oversupply of nutrients, and ultimately draining the oxygen necessary to support aquatic life. As for the impact of fertilizers on soil productivity, this diminishes over time, requiring the application of ever greater quantities in order to maintain yields.

Deforestation

Arguably the biggest losers from 20 th century economic growth were the forests of the world’s tropical regions and their non-human inhabitants. Across Africa, Asia, and the Americas, approximately one-third of forest cover has been lost. Because about half of the world’s species inhabits tropical rainforests, these clearances have had a devastating impact on biodiversity    , with extinction    rates now greater than they have been since the end of the dinosaur era, 65 million years ago. Much of the cleared land was converted to agriculture, so that the amount of irrigated soils increased fivefold over the century, from 50 to 250m hectares. Fully 40% of the terrestrial earth’s total organic output is currently committed to human use. But we are now reaching the ceiling of productive land expansion, in terms of sheer area, while the continued productivity of arable land is threatened by salinity, acidity and toxic metal levels that have now degraded soils across one third of the earth’s surface, some of them irreversibly.

Global Forest Map
Global Forest Map Since the middle of the twentieth century, the global logging industry, and hence large-scale deforestation, has shifted from the North Atlantic countries to the forests of tropical regions such as Indonesia and the Amazon Basin in Latin America. This tropical “green belt” is now rapidly diminishing, with devastating consequences for local ecosystems, water resources, and global climate. Source: NASA

Wetlands drainage and damming

Meanwhile, the worlds’ vital wetlands, until recently viewed as useless swamps, have been ruthlessly drained—15% worldwide, but over half in Europe and North America. The draining of wetlands has gone hand in hand with large-scale hydro-engineering projects that proliferated through the last century, such that now some two-thirds of the world’s fresh water passes through dam systems, while rivers have been blocked, channeled, and re-routed to provide energy, irrigation for farming, and water for urban development. The long-term impacts of these projects were rarely considered in the planning stages, and collectively they constitute a wholesale re-engineering of the planet’s hydrological system in ways that will be difficult to adapt to the population growth demands and changing climatic conditions of the 21 st century. As for the world’s oceans, these increasingly show signs of acidification due to carbon emissions, threatening the aquatic food chain and fish stocks for human consumption, while on the surface, the oceans now serve as a global conveyor belt for colossal amounts of non-degradable plastic debris.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Sustainability: a comprehensive foundation. OpenStax CNX. Nov 11, 2013 Download for free at http://legacy.cnx.org/content/col11325/1.43
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