[yellow grass]

Of course it is. There is a pretty robust consensus on the scientific community that it is happening. However, there are important sectors in society that do not agree, with reason or not. What is your opinion?

Here a pretty nice video showing the warming
Since 1850 the world has warmed by about 1°C and approximately half of this warming has occurred since 1990!

Full disclosure. I'm a climate scientist, and I don't know many skeptical (on climate change) people. It would be nice to understand your reasons if you are a global warming skeptic.

 

[64794]

It is actually the climate change, rather than global warming, which was the false term from the get go.

As for the issue itself, my earlier and much talked thread could be a referance point for the MTFers' stance.

France records its all-time hottest temperature, a...

What is going on with our planet? :sad:

www.menstennisforums.com

 

[yellow grass]

It is actually the climate change, rather than global warming, which was the false term from the get go.

Being totally honest, me and most other scientists don't really pay attention to semantics and use both terms, mostly interchangeable. However, for this discussion the term "global warming" is the appropriate one, as I want to talk about the very rapid warming that has occurred since ~ 1850s and continue today, mostly caused by humans. Climate change is less specific, as it refers to changes in climate (redundant I know) that has occurred over any timescale (climate has warmed and cooled over its long history), and also includes changes due to internal variability (climate changes with El Niño events for example), independent of external forcing due to humans.

A good reference is this one Overview: Weather, Global Warming and Climate Change

As for the issue itself, my earlier and much talked thread could be a referance point for the MTFers' stance.

France records its all-time hottest temperature, a...

What is going on with our planet? :sad:

www.menstennisforums.com

Thank you for pointing the thread. Actually, one of my areas of research is heat waves. The bottom line is: heat waves will not necessarily increase in number under global warming, but they will become longer, especially the more extreme ones.

 

[BodyServe]

Yes it obviously is but i don't like when it is used as a power grab or as a mean to get more money, also this divert the public from real problems like deforestation and human encroachment.

 

[guitarra]

Of course it is.

And now watch the deniers crawling out of their caves...

 

[-Dominator-]

Yes and it is also very likely to be a result of human activity given the correlation between temperature and human activity over the past 200 years or so. However, I've always failed to see how the emission of carbon dioxide is supposed to be the biggest problem of this planet with all the other severe damages humans cause to the planet.

 

[-Dominator-]

Since I generally dislike "discussions" like this one where everybody basically agrees with each other and everything is just boring, let me do what I always do (especially when trying to provoke some of the annoying die-hard fair-weather activists) and deny the influence of carbon dioxide on the rising temperature. I am open for discussions, feel free to convince me.

 

[Djoker]

This is a not a "climate change", but a planet change. Leave it at that...

 

[MWW]

Yes and it is also very likely to be a result of human activity given the correlation between temperature and human activity over the past 200 years or so. However, I've always failed to see how the emission of carbon dioxide is supposed to be the biggest problem of this planet with all the other severe damages humans cause to the planet.

Well carbon is a decent proxy for mass consumption.

 

[sheep85]

one of the supposed leaders of the western world once said global warming is a hoax by the chinese.
or was it the dems? can't remember.

 

[64794]

Recommending this decent doc

Before the Flood (2016) - IMDb

Directed by Fisher Stevens. With Leonardo DiCaprio, Ki-moon Ban, Alejandro G. Iñárritu, Mike Brune. A look at how climate change affects our environment and what society can do to prevent the demise of endangered species, ecosystems and native communities across the planet.

www.imdb.com

 

[-Dominator-]

Well carbon is a decent proxy for mass consumption.

It may be an indicator, but the person buying the car with the lowest CO2 emission every year is definitely not helping to protect the enviromenment and certainly is more damaging than the person driving their same "dirty" one for 30 years.

 

[-Dominator-]

Here in Germany the politicians are doing everything they can to protect the environment. One thing I generally like is promoting is the traffic by train. The Deutsche Bahn is obviously not maintaining and closing railways continuosly because they have to pay for their maintenance themselves while new railways are payed by the state and the politics (the EU) are sanctioning the transport of cargo by train to protect the car industry (just look at the difference between EU and Switzerland when it comes to freight traffic by train), BUT we are now having green instead of red stripes on trains to show everybody how much we care for the environment. In my honest opinion this is more than enough, you got to start somewhere, right?

 

[Pedigree]

Here in Germany the politicians are doing everything they can to protect the environment. One thing I generally like is promoting is the traffic by train. The Deutsche Bahn is obviously not maintaining and closing railways continuosly because they have to pay for their maintenance themselves while new railways are payed by the state and the politics (the EU) are sanctioning the transport of cargo by train to protect the car industry (just look at the difference between EU and Switzerland when it comes to freight traffic by train), BUT we are now having green instead of red stripes on trains to show everybody how much we care for the environment. In my honest opinion this is more than enough, you got to start somewhere, right?

Didn’t the Germans recently swear off nuclear power, which is currently by far the most realistic way to decarbonize our energy sources?

 

[-Dominator-]

Didn’t the Germans recently swear off nuclear power, which is currently by far the most realistic way to decarbonize our energy sources?

Yes. But they also want to leave coal power, until 2038.

 

[yellow grass]

let me do what I always do (especially when trying to provoke some of the annoying die-hard fair-weather activists) and deny the influence of carbon dioxide on the rising temperature. I am open for discussions, feel free to convince me.

Do you mean the physics behind the connection between carbon dioxide and temperature? If that's the case I wrote something below.

The role of carbon dioxide (and other greenhouse gases, such as methane and water vapor) in regulating the temperature of the planet is relatively straightforward. I'll divide this into feedback 1: the direct effect of increases in CO2, and feedback 2: the indirect effect.

Feedback 1. Carbon dioxide concentration is very little by mass but has strong radiative effects. This radiative effect occurs because carbon dioxide preferentially absorbs radiation in the infrared, which is then re-emited. So, basically solar radiation, with most of the spectrum being in the visible range, gets to the ground relatively unimpeded. This heats the earth, which in turns radiates back to space, with the bulk of the radiation in the infrared*. Since carbon dioxide is efficient at absorbing at the infrared, a good portion of the energy radiated by the earth is trapped in the atmosphere, which then heats it and radiates back a portion to the earth heating it more. This is basically the greenhouse effect, and is key to human survival. Without this effect the earth temperature would be approximately 33C lower. Now, the problem is that with higher man-made CO2 concentrations this effect occurs a little bit too much than before, so the earth equilibrium temperature rises. Now, by itself, increases in CO2 would yield about a quarter of the heating that what models project for end of the century, and the rest is given by the indirect effect (feedback 2).

Feedback 2. CO2 increases give the first kick to increases in temperature. When temperature increases the amount of water vapor also increases**. Water vapor is actually a stronger greenhouse gas compared to carbon dioxide. So, taking that into account, increases in water vapor (due to increases in CO2 and other greenhouse gases) is the main driver of already observed and future increases in temperature.

*it turns out there is a temperature - peak of radiation spectrum relationship, higher temperature objects preferentially radiates at the higher energy end: visible, ultraviolet, so forth.

**close to exponentially, in what is known as the Clausius-Clapeyron relation (Clausius–Clapeyron relation - Wikipedia). Hot places can have quite a bit more of water vapor before it condenses. Same amount of water vapor in a colder place would just form water droplets and eventually rain.

 

[Iblis_00]

False dichotomy.

 

[redshift36188]

Yes and it is also very likely to be a result of human activity given the correlation between temperature and human activity over the past 200 years or so. However, I've always failed to see how the emission of carbon dioxide is supposed to be the biggest problem of this planet with all the other severe damages humans cause to the planet.

The trend seems to be dry regions getting drier and wet regions getting wetter*. Less farmland as a result. Sea rise can also displace millions of people and wreck lots of cities, causing a lot of trouble in terms of a country's organisation. I'm not sure if it's the most damaging, but it's definitely very disruptive.

* @yellow grass correct me if I'm wrong

Didn’t the Germans recently swear off nuclear power, which is currently by far the most realistic way to decarbonize our energy sources?

Nuclear EROEI is fairly low if you take into account the whole life cycle of a nuclear plant. Better go for renewables.

Covid19, economic depression are realistic ways, but then again maybe not if it forces society back to massive consumption of wood and coal.

 

[-Dominator-]

The trend seems to be dry regions getting drier and wet regions getting wetter*. Less farmland as a result. Sea rise can also displace millions of people and wreck lots of cities, causing a lot of trouble in terms of a country's organisation. I'm not sure if it's the most damaging, but it's definitely very disruptive.

* @yellow grass correct me if I'm wrong

I've always thought the scenario drawn in Interstellar was a pretty accurate one and I suspect that's what the future will look like (unless humanity destroys itself first with a nuclear war or something like that). Bigger cities at the expense of farmland, farmland at the expense of forests and increasing commercial use of forests and monocultures. All of that with rising temperatures eventually leading into an increased desertification, less unsable farmland, lower quality of the used farmland because of its overuse, increasing problems with pests and so on.

 

[yellow grass]

The trend seems to be dry regions getting drier and wet regions getting wetter*.

* @yellow grass correct me if I'm wrong

You're absolutely correct. It's called the wet get wetter (or rich get richer) mechanism. Incidentally, my previous postdoc supervisor was one of the main researchers behind this idea, and wrote several of the seminal papers on it.

Basically, wet regions get increases in mean* precipitation and dry regions get decreases. Overall, because more moisture available, the total precipitation integrated over the globe increases under global warming.

*Extreme precipitation increases faster than the mean, so some dry regions with decreased mean precipitation may still experience more frequent extreme events (the ones that lead to flooding and which are generally more societally impactful).