All human emissions of greenhouse gases will have some effect on the climates of the world, no matter how small those emissions were.
The homo genus (us) is believed to have first started using fire as far back as 1.7 million years ago. Even that first fire would have had an impact on the climate, albeit of truly miniscule proportions.
It’s not really until we began to industrialise the world, starting around 1750, that human activities began to influence the climate to any appreciable extent. Even then, the global population was small in comparison with today (791 million opposed to 7,210 million) and per-capita emissions were a fraction of current levels. All told, emissions back then would have been in the order of 3% of current levels, enough to influence the climate to some degree but not appreciably so.
It would take another 150 years of ever increasing anthropogenic emissions before the point was reached where natural variability was exceeded.
Within the global climates there is an inherent natural variation, the factors are numerous and complex and simultaneously they cause warming and cooling – the overall net sum determines whether the global climates warm or cool. On decadal time scales the climates can go either way, on centennial timescales the climates should be fairly balanced, on millennial timescales and beyond we’re in different cooling phases.
Even today, the bulk of climatic influence is from natural causes. To apply some sort of perspective, Earth’s climate is warmed by about 34°C due to the presence of greenhouse gases in the atmosphere. Of this, some 33°C is natural, our contribution is the 1°C on top. Whilst it’s a proportionately small amount, it has a disproportionately large influence on our climates.
Matters are further compounded by significant natural decadal influences. If these work in opposition to human caused warming, as they have been doing for the last 15 years or so, they can cancel out most of the human warming influence. Similarly, natural influences can swing into a positive phase and amplify the human warming signature, as happened in the 80’s and 90’s and will do again in the coming 20 to 30 years.
Is a native American natural? Is an Amazonian Indian natural? How about a Masai tribesman. They do have metal work. Where do we draw the line? Natural is one of those words like climate change that is poorly defined and has a flexible definition depending on what you want it to mean. It is a tough question. Humans are a bipedal ape and have descended from a long line of bipedal apes. Trying to separate our lineage from natural and unnatural is impossible and if you tried it would be arbitrary and subjective. Humans causing fires isn't necessarily significantly affecting climate except as it might change the environment slightly. Burning plants simply puts the CO2 that the plants took out of the atmosphere back into it. In addition, natural fires occur so it would be exceedingly complex to try to estimate how much CO2 was added before it would have burned anyway. It is silly to try to go back that far. We still don't know how much our emissions have affected the climate but IMO the concentrations in the 1950s were enough that it might have measurably affected climate if there was some way we could figure out what it would have been naturally which we can't.
It still is. The climate is never the same, it's always changing. There is no such thing as a static climate. The earth has warmed slightly over the last 25 years. If the planet didn't warm, it would have cooled. In the 1970's the planet was cooling. Some of the same scientist claiming now that man is causing the planet to warm up were the same people saying that man was responsible for the planet cooling. Truth is, it's a big planet an man is too small to make any difference.
That's always been the case, until the last century.
There have been instances where there have been local disruptions.
Easter Island might be an example, with complete deforestation.
Other places, where forests were replaced by grasslands for livestock pasture would be another example.
However world wide climate change caused by our release of CO2 into the atmosphere on a large scale has only been possible within the last few decades.
BTW, you'll see folks like Maxx, Sagebrush, Kano, Cyclops, Jello, OttawaMike, BB, JimZ, and more, who all global warming deniers, say it's not warming.
And their favorite website, wattsupwiththat and many more are blogs that say neither tobacco nor global warming, are problems.
Just ignore 'em.
Even when hundreds of the Kuwaiti oil wells were on fire, it did not cause climate change. The dropping of nuclear weapons during WWII did not cause climate change. WWII with all of it's build-up of industrial might around the planet did not cause climate change.
So the answer to your question is that human activity simply does not cause climate change. Keep in mind that climate is the average of the weather over a long period of time, like 30 years or more. Humans are too trivial to do that.
The Sun sends us about 200 times more energy in a single day than all electrical production worldwide for a YEAR. Think about that and then decide if humans could significantly alter climate. https://ca.answers.yahoo.com/question/in...
Natural cycles have ALWAYS been in command of climate and humans never have.
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The date usually given for the beginning of the Industrial Age is 1835. Soon after that date the use of fossil fuels began on an increasingly large scale. First coal and later oil. Post WW1 the hunt for oil was in full swing as the automobile began to rapidly replace the horse. The massive expansion of the use of fossil fuels between the wars and in the post war world wiped out all 'natural forces'.
In the past before modern man began emitting pollution and various gases into the atmosphere. Thing such as the comings and goings of ice ages, the little ice age, the medieval warm period, and so on. Every climate aspect going on today has at least some small portion of human contribution to it. A lot of these things would occur with or without human contribution but human contribution either exacerbates or mitigates it.
The date usually given for the beginning of the Industrial Age is 1835. Soon after that date the use of fossil fuels began on an increasingly large scale. First coal and later oil. Post WW1 the hunt for oil was in full swing as the automobile began to rapidly replace the horse. The massive expansion of the use of fossil fuels between the wars and in the post war world wiped out all 'natural forces'.
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
It depends on what you define as natural. Is man natural? Are we a part of nature?
All the time, however some research suggests that it has been speeded up by pollution. Big business has spent a lot on politicians and propaganda to shield the full blame.
It depends on what you define as natural. Is man natural? Are we a part of nature?
The time before humans stopped being hunter gatherers, and started being agriculture farmers.
The time before humans stopped being hunter gatherers, and started being agriculture farmers.
The date usually given for the beginning of the Industrial Age is 1835. Soon after that date the use of fossil fuels began on an increasingly large scale. First coal and later oil. Post WW1 the hunt for oil was in full swing as the automobile began to rapidly replace the horse. The massive expansion of the use of fossil fuels between the wars and in the post war world wiped out all 'natural forces'.
The time before humans stopped being hunter gatherers, and started being agriculture farmers.
The time before humans stopped being hunter gatherers, and started being agriculture farmers.
It depends on what you define as natural. Is man natural? Are we a part of nature?
The time before humans stopped being hunter gatherers, and started being agriculture farmers.
It depends on what you define as natural. Is man natural? Are we a part of nature?
that would be all the time
It was called the first 4.5 billion years.
I really don't know that answer, but that is a very good question. #elliottshifman
increase of globel warming
