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Nasa Happily Reports the Earth Is Greener

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Re: Nasa Happily Reports the Earth Is Greener

#131

Post by ph0rque »

denisvlr wrote: post #99

On a related note, here is a discussion about how many trees it would take to solve climate change: https://earthscience.stackexchange.com/questions/2639/how-ma...

Here's an up-to-date study and discussion of that question: https://news.ycombinator.com/item?id=19248716

The number of trees needed (1.2T) is pretty close to the estimation of the accepted answer in your link (1.5T). The difference is, the up-to-date study has found that there is enough space for the trees. Now we just need to plant them :)

Re: Nasa Happily Reports the Earth Is Greener

#133

Post by SiempreViernes »

keiferski wrote: post #11

Serious question from a non-climate scientist: would an increase in global temperatures due to climate change ultimately cause more greenery, due to new growth in previously too-cold areas?

There is less surface around the poles, and previously ok-hot areas at the equator are now likely to become too-hot areas, so it's a net loss in this simple model.

A slightly more nuanced discussion upthread here: https://news.ycombinator.com/item?id=19263836

Re: Nasa Happily Reports the Earth Is Greener

#134

Post by mistrial9 »

setgree wrote: post #119

> “When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance. Now, with the MODIS data that lets us understand the phenomenon at really small scales, we see that humans are also contributing.” That global warming may induce more agriculture, and fo…

https://www.usda.gov/oce/climate_change/FoodSecurity2015Asse...

Re: Nasa Happily Reports the Earth Is Greener

#135

Post by theli0nheart »

NeedMoreTea wrote: post #107
mrfusion wrote: post #103

Earlier quoted context omitted.

I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes. Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.

For crops that tolerate the extra heat. Those which don't will need to be grown further toward the poles, which will reduce the length of growing season.

Plants adapt. The ones that can tolerate the extra heat will survive better and therefore propagate more than plants that don't.

Re: Nasa Happily Reports the Earth Is Greener

#136

Post by Wowfunhappy »

marcosdumay wrote: post #127
setgree wrote: post #119

> “When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance. Now, with the MODIS data that lets us understand the phenomenon at really small scales, we see that humans are also contributing.” That global warming may induce more agriculture, and fo…

I doubt anybody really knows. It is well known that CO2 improves plants growth. It is also well known that plants grow better within a narrow band of temperatures. Increasing both the CO2 contents of the atmosphere and Earth's temperature will have some complex results where on the places within that temperature band, plants grow slightly faster, on places that cross from too cold into the band plants grow much faste…

These all seem like variables a robust computer model could account for, no?

Re: Nasa Happily Reports the Earth Is Greener

#137

Post by BurningFrog »

NeedMoreTea wrote: post #107
mrfusion wrote: post #103

Earlier quoted context omitted.

I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes. Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.

For crops that tolerate the extra heat. Those which don't will need to be grown further toward the poles, which will reduce the length of growing season.

Reseeding a field with a new crop is technology known since thousands of years.

I don't think there is any risk of areas reaching temperatures too hot for any plants?

> which will reduce the length of growing season

Why?

Re: Nasa Happily Reports the Earth Is Greener

#138

Post by maratd »

hannob wrote: post #125
hirundo wrote: post #124

Earlier quoted context omitted.

What Rising CO2 Means for Global Food Security: http://co2coalition.org/wp-content/uploads/2019/02/Rising_CO...

The CO2 Coalition is a pseudoscientific climate denial organization.

Perhaps rather than an ad-hominem you can instead argue the point being made?

Re: Nasa Happily Reports the Earth Is Greener

#139

Post by hannob »

maratd wrote: post #138
hannob wrote: post #125

Earlier quoted context omitted.

The CO2 Coalition is a pseudoscientific climate denial organization.

Perhaps rather than an ad-hominem you can instead argue the point being made?

Okay, here's the thing: If you have plants with more or less CO2 under otherwise the same conditions you'll have more growth in the plants.

However that's not how the planet works. If you put more CO2 in the atmosphere you'll have for example rising sealevels and larger deserts (and probably more effects that diminish food production). You can't just pick a single effect of increased CO2 in isolation. (Except of course that's what the CO2 coalition does, because they chose to believe fairytales instead of science on climate change.)

This is just the obvious flaw in that argument. If you want the details and all the science there's a chapter on food security in the IPCC report: https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap... It discusses potential yields as well.

Re: Nasa Happily Reports the Earth Is Greener

#140

Post by mturmon »

twic wrote: post #93

> It’s called the Moderate Resolution Imaging Spectroradiometer, or MODIS, and its high-resolution data provides very accurate information So is the resolution high or moderate?

This is a fun question, and as an occasional user of MODIS products, I've asked it (to myself) also. Although I've never asked anyone on the MODIS team, who I see from time to time.

I have always supposed that they wanted to leave the door open for actual high (spatial) resolution observations in the future. The driving design requirement was for global coverage every two days, so this meant a wide field of view of the downward-looking optics (2200 km wide FOV) which in turn meant "moderate" spatial resolution.

It was designed in the early 1990s. If you look at the original MODIS design papers (e.g., The Moderate Resolution Imaging Spectrometer (MODIS) Science and Data System Requirements, IEEE TGARS, Jan. 1991), you read the design was inspired by instruments like AVHRR and HIRS. The "VHR" in AVHRR stands for "Very High Resolution" and it was 1km! And the H in HIRS stands for High-resolution and it was > 1km, as much as 10km (!!). So calling it "Moderate" seems like a corrective message to the community.

Why would you need more? Many of the MODIS products are 1000m X 1000m, which is too coarse for many "field-scale" applications, where you want to get down to the health of individual fields of crops, or mixed suburban/rural areas, or biomes where vegetation types are mixed at local scales.

For instance, transpiration from broad-leafed trees is very different from grasses, and "mixed pixels" of these two types can confuse models. Or scattered parking lots at the fringe of suburban areas impinging on vegetation.

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