What percentage of the global greenhouse gas emissions does the transportation sector emit?

what percentage of the global greenhouse gas emissions does the transportation sector emit?

14% by warming potential.

CO2 emissions by source

One thing you need to learn if you are interested in climate change is that all numbers are fuzzy, not because they are inaccurate, but because there are different ways to ask a single question.

About 90% of the CO2 we emit which is raising atmospheric levels comes from fossil fuels, which are easiest to divide into coal, petroleum and natural gas for a conversation like this.

The rest comes from deforestation, reduced soil health in agricultural lands, and increasing deserts.

,You can get somewhat different numbers if you ask about the natural carbon cycle.

For all of human history the atmosphere has been slowly changing from about 175 ppm to about 275 ppm CO2.

This is/was the end of the last cold spell in the ice age.

We are technically still in the ice age, although this is an extended peak interglacial period.

,Every year the atmosphere sees the highest level of CO2 in May, and the lowest level the following September or October.

The changes are due to all the growth and death of plants on land and in the ocean, but the driver of the changes seem to be Northern Hemisphere land-based plant growth.

This cycle has been around for hundreds of millions of years.

,The Ice Age changes are due to shifts in the Earthu2019s orbit and distance from the Sun known as the Milankovich cycles.

There is plenty to read about them online.

In the ice age, CO2 (and methane) in the atmosphere follows temperature change, and acts as a feedback to magnify the direct change in warming due to the Earth being a little closer to the sun.

,The sun also changes its heat output on an irregular cycle, which lasts between nine and fourteen years on average, but which can disappear for several cycles in a row.

,All of these factors affect plant growth, and that affects CO2.

But before humans, this all operated in a balanced system which took hundreds of thousands of years to shift much.

Since we started using fossil fuels we have raised atmospheric CO2 from about 275 ppm to about 417 ppm (May of this year).

Thatu2019s enough by itself to change the Earthu2019s temperature by more than one degree F.

But CO2 is the greenhouse gas which we are changing the most.

It is neither the only greenhouse gas, nor the one with the largest natural impact.

Water vapor has more impact than CO2, but raising CO2 is increasing the water vapor in the atmosphere.

,Thatu2019s a quick sketch of the situation.

In late 2017 the cost of utility scale wind and solar farms (about a half square mile, 50 MWu2019s and $50 million is a good lower limit for u201cutility scale.

u201d Although some smaller projects are being built they cost more per MWh of output.

This means that we can replace all the fossil fuels we use with renewable electricity.

Itu2019s a longer conversation than I want to type right now, but we can use renewable electricity to make hydrogen, and from that we can replace everything that we presently get from fossil fuels, and almost all of it for less money.

Search for u201cCarbon Engineeringu201d to get a sense of where we are going with this.

,Dying leaves and small plants will remain the largest source of CO2.

But the problem with climate change is not natural.

It is that we are taking carbon which was removed from the atmosphere over many millions of years, and putting it back into the atmosphere in a couple of centuries.

If we want to stop this, we have to do a lot of things.

But if we use renewable wind and solar and energy efficiency to end fossil fuel consumption, all the other things will work.

If we donu2019t, there is no point in doing the other things.

,Until late 2017 it was hard to point to a clear alternative to fossil fuels which made economic sense.

Today, not solving climate change costs more than solving it.

The only remaining question is whether we end fossil fuels as fast as possible, or something less than that.

What is carbon emissions

the gases generation from fossil fuel burning & waste generated by us of all activities include home , industries, vehicles u2026.

.

,so try to cut down all possible way fossil fuel burning & waste generation

How many greenhouse gases are there

There are actually dozens or hundreds of greenhouse gases.

Any molecule that can absorb infrared radiation and store it as vibrational kinetic energy is a greenhouse gas.

The IPCC has prepared a reference list of the relative potency of a number of common industrial chemicals by comparing them to CO2:,2.

10.

2 Direct Global Warming PotentialsNote that several of these molecules are hundreds or thousands of times more potent greenhouse gases than CO2; however, they are also found at far lower concentrations in the atmosphere.

,The most commonly mentioned greenhouse gases are carbon dioxide (CO2), methane (CH4; about 25 times more potent than CO2), and nitrous oxide (N2O about 300 times more potent than CO2).

,Note that water vapor, which is often cited as being a greenhouse gas, is not on the IPCC radiative forcing list because that list is meant to compare the relative effects long-persisting substances.

Water vapor is constantly cycling through the atmosphere and a specific direct emission of water vapor does not remain in the atmosphere for long enough to register.

The most common basis for evaluating global warming potentials looks at a 100-year time scale; water vapor remains in the atmosphere for about 9 days (http://www.

eso.

org/gen-fac/pubs/astclim/espas/pwv/mockler.

html) ,However, water vapor that reaches the upper troposphere or above (starting at about 5km up) can have a significant impact on the climate system.

Upper tropospheric water vapor is an important potential feedback mechanism that may accelerate global warming.

Climate simulation models must therefore attempt to simulate the movement of water vapor in the atmosphere and estimate changes in water vapor content at high altitudes (e.

g.

https://www.

rsmas.

miami.

edu/news-events/press-releases/2014/new-study-confirms-water-vapor-as-global-warming-amplifier)

Global CO2 emissions

Global average temperatures have increased by about 1u2103 since pre-industrial times.

Human emissions of carbon dioxide are the likely cause of that rise.

,Donu2019t think that this is bad.

A small global rise in temperature is good for humanity as well as the ecosystem.

The main effect that the rise is CO2 has had is that the Earth is greener now than it had been a few decades ago.

,Thatu2019s because plant life is u2018happieru2019 with more CO2 in the atmosphere.

Hereu2019s one of the many articles about this: Study Finds Plant Growth Surges as CO2 Levels Rise.

,u201cThe carbon dioxide fertilization effect from all other influences and calculated that this could account for an 11 percent increase in global foliage since 1982.

u201d This is true even though there are, sadly, large losses of rain forest areas.

,Think about actual greenhouses.

They intentionally pump in CO2 in order for plants to grow faster.

The above graph shows that a CO2 concentration of 800 to 1000 ppm is best for most plants.

Our current atmospheric CO2 average is about 410 ppm.

,Iu2019m not suggesting that we intentionally add more CO2 into the atmosphere, because it does slightly increase global temperatures.

Also, it is very likely that before the end of this century, weu2019ll be utilizing energy from renewables and nuclear power, thus essentially humanity will stop contributing CO2 to the atmosphere.

,Furthermore, a warmer climate means longer growing seasons in Western Europe, Canada, the upper part of the United States, Russia, and many other countries.

,So far, the increase in CO2 has been a net positive.

Greenhouse gases and global warming

The atmospheric greenhouse effect maintains a surface warming of 33C degrees over the temperature produced by solar radiation alone.

,As additional greenhouse gases such as water vapor, carbon dioxide and methane enter the atmosphere that greenhouse effect is enhanced or strengthened forcing an upward trend in surface temperatures.

,Water vapor is the most important greenhouse gas to the instantaneous greenhouse effect, that which is acting at any moment in time.

However, water vapor is a condensible gas which precipitates out of the atmosphere in a relationship dependent upon temperature.

Thus itu2019s concentration in the atmosphere is a feedback to the current global mean temperature.

It can not drive the temperature upward in a sustained manner.

Water vapor and water clouds together produce about 75% of the instantaneous greenhouse effect.

,CO2 on the other hand is a non-condensible greenhouse gas.

Thus it accumulates in the atmosphere until other very slow processes can remove it.

It therefore drives up the temperature in a sustained manner over time.

CO2 contributes about 20% to the instantaneous greenhouse effect, but is responsible for nearly all the longer term upward trend in temperature because of itu2019s continued presence as it accumulates .

,Methane is also a very powerful greenhouse gas, since there is so little of it present, adding even a little more has a strong effect.

It has an atmospheric resident time of about 20 years, but breaks down to CO2 and water vapor in the presence of ultraviolet radiation from the Sun.