United is on the edge of separation from Boeing's NMA program

I don't understand why this particular article generates a discussion (argument?) about climate change...
Is this not more about United's timeline for fleet renewal and the candidate aircraft available to be considered?

There is technology and then there is economics. The real world of commercial aviation is skewed by opaque accounting practices (lasts as long as they can get away with these). I only hope that we sustain the flow of commercial pilots with living wages to maintain the advances in aviation.

It sounds like a lot of pre-merger Continental management are still at United. Continental was very committed to Boeing as the sole provider of their mainline fleet.
As to the A321XLR being "better", the base A321 without auxiliary fuel tanks is not able to cruise anywhere near as far as the base 757-200, which never had auxiliary fuel tanks. The biggest mistake with scrapping the 757 program was doing so before ETOPS became a thing. Foreknowledge could have prevented this mess, but it wasn't there. Had Boeing not decided to go with the stretched 737NG and ultimately the MAX, we would have seen a newer, more efficient version of the 757 series. It's a shame that the MAX being unbalanced would lead to major delays in the NMA project, which would make Airbus eat up even more of a market share. Heck, if Boeing offered auxiliary fuel tanks on a revamped 757 aircraft, it would be able to cruise much further than the A321 in any form.
Either way, Boeing is paying the price for bad decisions, and Airbus is eating up Boeing's mistakes.

This “99%” figure is all the more reason you make us believe that everything else in your statement is merely hyperbole.

Perhaps (I have no inside info so take the perhaps seriously) Boeing is not so much distracted by the 737 MAX debacle as it is learning from it and making sure they get their NMA right.

I prefer the Airbus.

Right now Boeing leadership is a little distracted..and with 99 percent of the worlds scientists agreeing Global warming is a thing and caused by human activity, not a natural heating cycle, maybe Boeing is really struggling with the next generational alternatives

From someone with no knowledge of aircraft design maintenance etc. Why can't an older aircraft be fitted with newer engines?

I have tried for months to buy tickets from UAL on a direct flight from IAH to LHR. The cost of Business Class seats for me and my wife fluctuated daily between $20,834.46 and $5,841.46 for the exact same flight and seats. We finally bought a ride on British Airways and saved ourselves $2,100 compared to UAL. If this retail example of pricing strategy indicates how United manages maintenance, staffing and other aspects of their business, I can only wonder how long the once proud bird with the golden tail will remain aloft.

Why would anyone fly that airline anyway??? Worst ever.

Boeing is in no position to turn down United’s request for airplanes. Boeing should fix the MAX, rename it and sell to United.