That's not an argument, that's just a remark.
> Right now we're debating whether natural habitats can be protected while current consumption patterns are maintained and ramped up
Not with animal agriculture in the world we have (population growth, developing regions, overshoot, existing levels of deforestation and biodiversity loss etc.).
> high consumption is the preferred way of life, as expressed by people's choices
I don't think people have much choice to live how they'd like. Their choices are being forced by the system. Many would choose something else if it was possible.
> The world doesn't produce enough to provide every one with a basic income that provides a high quality of life and good housing
> per capita GDP and seeing that it's ~$18,000
If we're discussing UBI and degrowth, we must consider abolishing money as we know it now for various reasons.
Firstly, economics is not what most people think it is; it's a pseudoscience with imprecise models that often ignore negative externalities, such as environmental impacts, GDP is a meaningless metric, and the entire financial system is rigged.
Why is it rigged? A significant portion of the money in the economy is credit/debt, created by banks when someone takes out a loan. There is a premium on this money that must be paid, usually a few percent every year, and this leads to exponential growth. However, exponential growth is unsustainable in a finite environment like ours. While space and other planets might be options in the future, currently, this planet is all we have.
Around 40-70% of people are employed in bullshit jobs. These jobs are unnecessary or even harmful, consuming resources for commuting and job-related needs. People are forced to pretend they contribute just to secure a place to live and food in their fridge.
> to provide every one with a basic income that provides a high quality of life and good housing
Yet (almost) nobody dies of hunger (in our countries, anyway, nor should they) and (almost) everyone has a roof over his head, when the day ends. It's all a matter of distribution. We already produce enough food for 10B people, and e.g. US has enough free flats for every homeless person (and then some).
The problem is distribution, nothing else. Money doesn't work well in this regard.
> innovation to invent new healthcare technologies that can end the scourge of cancer, heart disease and other major illness is proportional to the productivity
Scientists would still work even with UBI. Doctors would too, as well as teachers and artists. They are all motivated by factors other than money. And they would be compensated too.
Currently, only 2% of people are employed in agriculture (and provide food for the 98%). However, even if we needed 6% for a more sustainable plant-based agricultural food production, under UBI, we could find individuals who would be happy to move from meaningless jobs to work in nature. People are not doing this now because they need to sustain themselves, and the current system doesn't allow for it. Money is not an accurate measure of value; we learned this when the COVID-19 pandemic began, and we realized that some sectors are more valuable than their compensation suggests.
Other sectors would also require people to work, and there would be different incentives, such as societal appreciation, travel credits, or the opportunity to switch from an apartment to a house with a bigger garden. We would find suitable motivations for individuals to contribute to these sectors.
> Raising productivity is a moral imperative
Degrowth is a moral imperative. Wait. You've been talking about production/consumption earlier, now about productivity. Those are not the same things.
https://en.wikipedia.org/wiki/Ecological_overshoot#/media/Fi...
This is how we're utilizing earth resources now. We're currently consuming 1.7 earth resources every year (overshootday.org). And you'd like to step on the gas?
> The degrowth ideological narrative is utterly baseless in its economic rationale
No, it's the current system that is broken and wrong.
https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...
Exponential Economist Meets Finite Physicist
https://libcom.org/article/phenomenon-bullshit-jobs-david-gr...
On the phenomenon of bullshit jobs - David Graeber
https://en.wikipedia.org/wiki/Universal_basic_income