What is your opinion on gobal warming?

Answer 1

The short, global climate change (global warming) is real. I want to explain below the difference between "natural processes" and "human influence" to give you a better picture of why global warming is so important. Here's my long version below:

Over the geologic timescale, the Earth has gone through natural variations in the amount of carbon dioxide. The long-term inorganic carbon-silicate weathering cycle accounts for these discrepancies. First, carbon dioxide is dissolved in rainwater which reacts to form carbonic acid. From there, the rainwater falls on land or ocean. On land, carbonic acid reacts with rocks and combines to form a bicarbonate ion through the process of weathering. These weathered carbonate materials are then carried to the ocean and form minerals on the ocean floor. The rocks that form the ocean floor are gradually carried toward the continental boundaries by plate tectonics, where the carbonate rock is subducted under the continental crust. The rock is then heated as it descends into the mantle, releasing the carbon dioxide and allowing it to escape and return to the atmosphere through volcanic eruptions. This ongoing cycle regulates the carbon dioxide content of the Earth’s atmosphere and acts as a thermostat to keep the Earth’s climate fairly stable. The cycle also ensures that most of the Earth’s carbon dioxide resides in carbonate minerals on the ocean floor rather than in the atmosphere as carbon dioxide gas.

This natural process on Earth has been a large factor to keep the planet’s climate conducive to life. The carbon-silicate weathering cycle is a “negative feedback” process. Although the word “negative” has an ominous connotation, it actually describes a feedback loop which allows the temperature of Earth to remain fairly constant over time. For example, there was a period known as “Snowball Earth” where the Earth was completely frozen. When the Earth was frozen, weathering of rocks ceased to exist because it was too cold for precipitation, the beginning of the weathering process. Because there was no weathering, carbon dioxide was not taken out of the air and placed into rocks. This led to a build-up of carbon dioxide in the Earth’s atmosphere. The increased carbon dioxide triggered a stronger greenhouse effect that caused the Earth to warm bringing it out of the Snowball Earth period.

The last paragraph described Earth’s feedback mechanism to manage natural sources of carbon dioxide over geologic time. However, carbon dioxide input in the past century has increased rapidly due to anthropogenic sources. Global Warming or Global Climate Change postulates that a net increase in greenhouse gases will lead to increased warming of the planet. This theory is based on observations from ice core records and forecasted trends from global climate models. Global mean surface temperatures have increased 0.5-1.0°F since the late 19th century from the beginning of the Industrial Revolution. Also, the 20th century's 10 warmest years all occurred in the last 15 years of the century. Of these, 1998 was the warmest year on record. Records at Mauna Loa, Hawaii have kept these records since 1960, prior to that year; ice core data has shown the same increase in carbon dioxide.

How can we know how much global warming will impact the Earth? Well, the computer models are getting better but there is still a lot of uncertainty. However, models that I have worked with have shown the temperature increase becoming much more significant over the next 10-30 years.

Here's a good link with graphics to help put it into perspective:
http://www.carleton.edu/departments/geol/DaveSTELLA/Carbon/carbon_intro.htm

Answer 2

There have been some good answers posted, and my intent providing this one is not so much that I expect it to be chosen as such, but so that the readers realize a few things:

We have only been taking accurate temperature measurements for several hundred years, and globally for only about the past 100 or slightly more. Anything else is based on indirect measurements and estimates of dubious accuracy. For example, we don't know for certain that air samples trapped in ice have never changed - given a long enough time, molecules can escape almost anything and their composition can change.

People started taking such records around 1700 - not long after the invention of the thermometer, Fahrenheit temperature scale etc. This was during a period referred to as the Little Ice Age, when cold weather was predominate over northern areas of the globe and especially northern Europe. People in North America wrote about how cold some of the winters during the late 1700's were.

Thus the above very significantly influenced people's notions of what normal temperatures are. Indeed, many climates were warm in past centuries - e.g., grapes growing in England in the 13th century - but there were no reliable measurements of exactly how warm.

So what I am saying is consider the possibility that after the presumed ice age 18000 years ago, the climate is still in the process of returning to normal - which is warmer than we think. What is it gonna do after an ice age, become colder? If an ice shelf breaks off, isn't this the same thing that's been occurring since? There will of course be some fluctuations in the process - note the purple line in figure 7.03 linked to in the answer above - that the climate was supposedly warmest around 7000 years ago. That is interesting, as it is that temperature would so abruptly level off afterward.

Regarding what the consequences of global warming are? Well, we've only had a little over an inch of snow in the Poconos thus far (pimarily because of El Niño, but global warming makes it a bit warmer still). The skiers hate it, but if this is a disaster I want more of them - don't have to bother with a foot or 2 of snow in my way all the time - can do things like chop wood on the bare ground outside. We've averaged about 65 inches of precipitation the past several years:

http://www.joseph-bartlo.net/mtpdat.htm

so it does not seem to be making the climate dry here ATTM.

I don't think global warming would destroy the ecosystem, and I think there will be plenty of places to grow food. The problem would be with people's reluctance/inability to adapt and change along with it as required. They would have to learn to cooperate better than they compete.

Answer 3

Some aspects are facts, not really subject to debate. These are:

The measured average global temperatures over the past 150 years have increased by about 1 deg C.

The atmospheric concentration of carbon dioxide began to increase following the industrial revolution and is now about 35% higher than it has been in the past.

The measured temperature increase has not been monotonic with time.

The post industrial revolution increase in CO2 has been monotonic with time.

Average global temperatures infered from ice core deuturim concentrations show a cyclic pattern. The lowest of these infered temperatures are about 8 deg C colder than the infered temperature of 1998, the highest were about 3 degrees higher. This cycle has existed for approximately 425,000 years. The cycles are approximately 100,000 years in duration.

The measured CO2 concentration of gas bubbles trapped in the same ice cores shows a very good correlation to the infered temperature. Periods with low CO2 concentrations correspond to low temperature periods. High CO2 concentrations correspond to high temperatures.

At the low points, CO2 concentrations are typically 180-185 ppmv. At the high points (pre industrial) 280-300 ppmv. Current CO2 concentrations are 370 ppmv.

These historical fluctuations in temperature and atmospheric CO2 are a natural process and not due to the human activity.

From this certain conclustions can be drawn:

There is more CO2 in the atmosphere than ever before this is due to human activity

The current temperature levels are still within the normal range of these historical cycles and below the historical maximums.

The rate of some past short term (20-100) year increases in temperature have been substancially greater than the current short term rate of warming seen in measured temperatures.

Answer 4

I believe it's slowly (or quickly, depending on view) happening. Southern Canada used to be almost as cold as the Arctic for many long months of the year. Now, cities such as Toronto, Montreal, and Halifax are seeing less snow and severe temperatures.

The west part of Canada is definitely getting hotter. Last summer, my small coastal home town saw several days over 30'C and 3 days at 40'C with absolutely no precipitation.

Palm trees are now a common sight in gardens and yards along the south coast of British Columbia and are now being tried in more inland places such as Kamloops and Kelowna. (Though I doubt that any palm could survive in the BC interior).

The effects of global warming are felt most strongly in Northern Canada, more than anywhere else on earth. There are fears that polar bears' habitat will eventually disappear along with that of Eskimos. These people have depended on the ice and snow to preserve their way of life. From fishing to transportation, their home is melting. Recently, a huge chunk of ice broke off Elsemeare Island (way up north), making it the world's largest iceberg.

Answer 5

An increase in global temperatures can in turn cause other changes, including a rising sea level and changes in the amount and pattern of precipitation. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences include higher or lower agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors. Warming is expected to affect the number and magnitude of these events; however, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has a long average atmospheric lifetime.

Answer 6

I am undecided on global warming. I have a tendency to question what I feel to be propaganda. I do think that we should take measures to limit any potentially harmful effects that people may cause on the environment. However, I am not entirely sure that the recent changes in the environment are resulting from mans production of greenhouse gasses and not a natural cycle.

Answer 7

in North Africa,India,Mexico ,millions of people are effected by land loss and desertification


in recent times thousands of people have died because of exessive heat,usually old people.in India ,Mexico and France,
deforestation causing desertification,the desert conditions causing very cold nights and scorching hot days

in china, thousands of what used to be farmers are running for their lives from the dust storms that have burried their towns and turned their lands into dessert,the globe where they were got to hot for them .
and instead of producing food they are now needing it from some where else,and they will drastically effect the world food prices when they start buying water in the form of grains ,at any cost destabalising governments, in some countries ,could be the result
(are you seeing more Chinese around interested in agricultural lands ,we do here in Mexico)

this was man made global warming because of over grazing and fertilizers, and they are not the only ones
collectively this planet is drying up ,the Sahara is growing by 7 kilometers a year
and all of the desserts we know are a results of mans actions ,and they are increasing ,not getting less ,in the dinosaurs days ,there were no desserts.

so as far as the food production is concerned Global warming or some of its effects are serious,rising seas result in landloss

each degree rise in temperature means 10%crop loss

more landloss because of desertification every year,we have less areble land to produce food ,for an extra 70 million people ,

and there is less and less water (because of deforestation),to irrigate this production ,
and there are less and less farmers to do it..
who are overpumping deep carbon aquifiers
who are plowing more and more unstable lands because they have lost so many million hectares to desertification ,
because of bad farming practises ,such as using fertilizers and heavy machinary or over grazing

RISING SEAS
The northpole is melting ,and we will know it without ice in our life times.
this does not affect the sea level because it is ice that is already in the water.but the melting ice from Green land and the south pole ,are another matter.

Global warming is in theory reversable,but it will mean global co operation between all countries ,and taking into account human nature and the world politics ,it is unlikely that this will happen,

At least not untill we are all in the middle of planetary disastres and it becomes a battle for the survival of humanity every where.

SOLUTIONS
if you want to help the planet ,plant a tree every week ,if everyone on the planet did we we would be able to reverse the destructive processes

reduce carbon emisions,and they are already working on that by alternative forms of energy and regulations on carbon producing materials,aerosol cans,burning rubbish,industrial chimneys,powerplants etc.

the capture of carbon and the production of water and assist the aquiferous manta.

the world bank pays large subsidies for reforrestation to capture carbon and the best tree for this is the Pawlonia

Waterharvesting projects ,such as millions of small dams.to redirect over ground waterflows from the rains into the ground to supply subteranian water supplies.

the protection of existing forrests.

stop building more highways,urban planning to include vegetation stop building cities encourage people to return to the land to conduct their business from there which now has become possible thanks to the internet.

education to motivate people to auto sufficiency by building more home food gardens.

education on environmental awareness
education on family planning to curb over´populaion

Agricultural education and improvements to follow the principals or sustainability and soil management.

more environmental or land ,design to prevent bush fires,such as--fire breaks

,more dams.regulations and control for public behaviour

alternative effeciant public transport to discourage the use of the internal conbustion engine

recicling wastes,limit water use

i am a Permaculture Consultant for the department of Ecology for the regional government in Guerrero Mexico
http://spaces.msn.com/byderule

Source(s) Lester E Brown is the director and founder of the global institute of Environment in the United states .he has compiled a report based on all the satalite information available from NASA,and all the information that has
come from Universities and American embassies WORLD WIDE ,
his little book--a planet under stress , Plan B has been trans lated into 50 languages and won the best book award in 2003.