That works up to a certain point, since the production is limited by the area of naturally occurring grasslands. When all the grassland is used, forests are cleared. Today, grazing is responsible for 80% of all deforestation in the Amazon [1].
At least the soil issues can be fixed through regenerative practices, which also help mitigate climate change to some extent. Farmers should receive funding to safely transition to better practices.
To reach the 2030 and 2050 targets (-45%, -100%), this change alone would be very insufficient. It would help during the second half of the century though, when emissions will likely need to be negative.
Yes, it would be more effective to reduce meat consumption globally. But we need to do both because time is running out. See the Drawdown project for an exhaustive list of policies.
I'd argue that people who actively work on climate change mitigation should keep flying if it really helps them be more effective. One of my friends does that: she helps urban planners save millions of tons of CO2, while emitting a few tons by herself. Overall, it's a good investment.
The plastic straw ban had almost nothing to do with climate activism, it's just a low priority measure to fight plastic pollution. These two issues are barely related.
The success of the UK's energy policy is undeniable. However they still have a long way to go in every other sector (transport, agriculture, imports..) before reaching carbon neutrality.
The practical solutions are well known in the community, see the Drawdown project for a pretty exhaustive list. Since we are very late in the fight against climate change, all of these solutions need to be implemented, so there's no point in promoting just a few of them.
I would rather risk a small decrease in my standard of living today than cause a worldwide genocide within a few years.
You might be interested by "The Happiness-Energy Paradox: Energy Use is Unrelated to Subjective Well-Being".
Earth’s per capita energy use continues to grow, despite technological advances and widespread calls for reduction in energy consumption. The negative environmental consequences are well known: resource depletion, pollution, and global warming. However many remain reluctant to cut energy consumption because of the widespread, although, implicit, belief that a nation’s well being depends on its energy consumption. This article systematically examines the evidential support for the relationship between energy use and subjective well-being at the societal level, by integrating data from multiple sources, collected at multiple levels of government, and spanning four decades. This analysis reveals, surprisingly, that the most common measure of subjective well-being, life satisfaction, is unrelated to energy use -- whether measured at the national, state or county level.