There has been a lot of discussion about negative emissions technologies (NETs) lately. While we need to be skeptical of assumed planetary-scale engineering and wary of moral hazard, we also need much greater RD&D funding to keep our options open. A quick thread: 1/10

Energy system models love NETs, particularly for very rapid mitigation scenarios like 1.5C (where the alternative is zero global emissions by 2040)! More problematically, they also like tons of NETs in 2C scenarios where NETs are less essential. https://t.co/M3ACyD4cv7 2/10
In model world the math is simple: very rapid mitigation is expensive today, particularly once you get outside the power sector, and technological advancement may make later NETs cheaper than near-term mitigation after a point. 3/10
This is, of course, problematic if the aim is to ensure that particular targets (such as well-below 2C) are met; betting that a "backstop" technology that does not exist today at any meaningful scale will save the day is a hell of a moral hazard. 4/10
Many models go completely overboard with CCS, seeing a future resurgence of coal and a large part of global primary energy occurring with carbon capture. For example, here is what the MESSAGE SSP2-1.9 scenario shows: 5/10
These modeled worlds of planetary-scale engineering (with, say, three times the land area of India devoted to bioenergy with carbon capture and storage) are pretty hard to imagine from the vantage of today, where we are struggling to get our act together on basic mitigation. 6/10
At the same time, there will be a real need for NETs, even if its not as the scale that some modelers dream of. There will be a long tail of hard-to-decarbonize sectors (agriculture, aviation, polymers, industrial heat) where NETs can cost-effectively offset limited emissions. 7/
Perhaps more importantly, one of the most pernicious aspects of climate change is that left to its own devices its effectively permanent (at least in human-relevant timescales). Even if we get all our emissions down to zero the Earth will just stop warming; it won't cool down. 8/
This means that if we ever want to return to a cooler climate after we reach zero emissions, we will need to actively remove CO2 from the atmosphere. Its not hard to imagine massive efforts in the 22nd century to reverse the damage of the 21st. 9/10
So lets continue to fund research and deployment of NETs to help drive down costs and drive future innovation. But lets be very careful to make sure we treat NETs as a compliment to rather than a replacement for mitigation. 10/10

More from Tech

A common misunderstanding about Agile and “Big Design Up Front”:

There’s nothing in the Agile Manifesto or Principles that states you should never have any idea what you’re trying to build.

You’re allowed to think about a desired outcome from the beginning.

It’s not Big Design Up Front if you do in-depth research to understand the user’s problem.

It’s not BDUF if you spend detailed time learning who needs this thing and why they need it.

It’s not BDUF if you help every team member know what success looks like.

Agile is about reducing risk.

It’s not Agile if you increase risk by starting your sprints with complete ignorance.

It’s not Agile if you don’t research.

Don’t make the mistake of shutting down critical understanding by labeling it Bg Design Up Front.

It would be a mistake to assume this research should only be done by designers and researchers.

Product management and developers also need to be out with the team, conducting the research.

Shared Understanding is the key objective


Big Design Up Front is a thing to avoid.

Defining all the functionality before coding is BDUF.

Drawing every screen and every pixel is BDUF.

Promising functionality (or delivery dates) to customers before development starts is BDUF.

These things shouldn’t happen in Agile.
I could create an entire twitter feed of things Facebook has tried to cover up since 2015. Where do you want to start, Mark and Sheryl? https://t.co/1trgupQEH9


Ok, here. Just one of the 236 mentions of Facebook in the under read but incredibly important interim report from Parliament. ht @CommonsCMS
https://t.co/gfhHCrOLeU


Let’s do another, this one to Senate Intel. Question: “Were you or CEO Mark Zuckerberg aware of the hiring of Joseph Chancellor?"
Answer "Facebook has over 30,000 employees. Senior management does not participate in day-today hiring decisions."


Or to @CommonsCMS: Question: "When did Mark Zuckerberg know about Cambridge Analytica?"
Answer: "He did not become aware of allegations CA may not have deleted data about FB users obtained through Dr. Kogan's app until March of 2018, when
these issues were raised in the media."


If you prefer visuals, watch this short clip after @IanCLucas rightly expresses concern about a Facebook exec failing to disclose info.
The 12 most important pieces of information and concepts I wish I knew about equity, as a software engineer.

A thread.

1. Equity is something Big Tech and high-growth companies award to software engineers at all levels. The more senior you are, the bigger the ratio can be:


2. Vesting, cliffs, refreshers, and sign-on clawbacks.

If you get awarded equity, you'll want to understand vesting and cliffs. A 1-year cliff is pretty common in most places that award equity.

Read more in this blog post I wrote:
https://t.co/WxQ9pQh2mY


3. Stock options / ESOPs.

The most common form of equity compensation at early-stage startups that are high-growth.

And there are *so* many pitfalls you'll want to be aware of. You need to do your research on this: I can't do justice in a tweet.

https://t.co/cudLn3ngqi


4. RSUs (Restricted Stock Units)

A common form of equity compensation for publicly traded companies and Big Tech. One of the easier types of equity to understand: https://t.co/a5xU1H9IHP

5. Double-trigger RSUs. Typically RSUs for pre-IPO companies. I got these at Uber.


6. ESPP: a (typically) amazing employee perk at publicly traded companies. There's always risk, but this plan can typically offer good upsides.

7. Phantom shares. An interesting setup similar to RSUs... but you don't own stocks. Not frequent, but e.g. Adyen goes with this plan.

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कुंडली में 12 भाव होते हैं। कैसे ज्योतिष द्वारा रोग के आंकलन करते समय कुंडली के विभिन्न भावों से गणना करते हैं आज इस पर चर्चा करेंगे।
कुण्डली को कालपुरुष की संज्ञा देकर इसमें शरीर के अंगों को स्थापित कर उनसे रोग, रोगेश, रोग को बढ़ाने घटाने वाले ग्रह


रोग की स्थिति में उत्प्रेरक का कार्य करने वाले ग्रह, आयुर्वेदिक/ऐलोपैथी/होमियोपैथी में से कौन कारगर होगा इसका आँकलन, रक्त विकार, रक्त और आपरेशन की स्थिति, कौन सा आंतरिक या बाहरी अंग प्रभावित होगा इत्यादि गणना करने में कुंडली का प्रयोग किया जाता है।


मेडिकल ज्योतिष में आज के समय में Dr. K. S. Charak का नाम निर्विवाद रूप से प्रथम स्थान रखता है। उनकी लिखी कई पुस्तकें आज इस क्षेत्र में नए ज्योतिषों का मार्गदर्शन कर रही हैं।
प्रथम भाव -
इस भाव से हम व्यक्ति की रोगप्रतिरोधक क्षमता, सिर, मष्तिस्क का विचार करते हैं।


द्वितीय भाव-
दाहिना नेत्र, मुख, वाणी, नाक, गर्दन व गले के ऊपरी भाग का विचार होता है।
तृतीय भाव-
अस्थि, गला,कान, हाथ, कंधे व छाती के आंतरिक अंगों का शुरुआती भाग इत्यादि।

चतुर्थ भाव- छाती व इसके आंतरिक अंग, जातक की मानसिक स्थिति/प्रकृति, स्तन आदि की गणना की जाती है


पंचम भाव-
जातक की बुद्धि व उसकी तीव्रता,पीठ, पसलियां,पेट, हृदय की स्थिति आंकलन में प्रयोग होता है।

षष्ठ भाव-
रोग भाव कहा जाता है। कुंडली मे इसके तत्कालिक भाव स्वामी, कालपुरुष कुंडली के स्वामी, दृष्टि संबंध, रोगेश की स्थिति, रोगेश के नक्षत्र औऱ रोगेश व भाव की डिग्री इत्यादि।