Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Carbon Dioxide, Fusion, and Stellarators   Much emotion is expended on the dangers of carbon dioxide, but solutions
require reason and recognition of facts: (1) The cost of developing options is
approximately a thousand times less than their deployment. (2) Timescales
involve two questions: (a) How quickly can an option be demonstrated? (b) How
quickly can the required equivalent of thousands of units be built. Two
questions are implied: (1) What options would most fundamentally change the
carbon-dioxide problem? (2) For each option, how could it be demonstrated most
quickly? An option of fundamental importance is direct air capture of carbon
dioxide. The option that appears most attractive for carbon-free energy
production is the stellarator fusion concept, which is poised for a rapid
demonstration.

30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga