Rev 8:7 The first angel sounded, and there followed hail and fire mingled with blood, and they were cast on the earth: and the third part of trees was burnt up, and all green grass was burnt up.
Hail represents judgment, trouble and war.
Exo 9:18 Behold, tomorrow about this time I will cause it to rain a very grievous hail, such as hath not been in Egypt since the day it was founded even until now.
Isa 28:17 Judgment also will I lay to the line, and righteousness to the plummet: and the hail shall sweep away the refuge of lies, and the waters shall overflow the hiding place.
Fire represents judgment, purification and revealing of sin. It can also represent a certain class of angels
Ps 66:10 For you, O God, have proved us: you have tried us, as silver is tried. 11 You brought us into the net; you laid affliction on our loins. 12 You have caused men to ride over our heads; we went through fire and through water: but you brought us out into a wealthy place.
Num 31:23 Every thing that may abide the fire, you shall make it go through the fire, and it shall be clean: nevertheless it shall be purified with the water of separation: and all that stays not the fire you shall make go through the water.
1Pet 1:7 That the trial of your faith, being much more precious than of gold that perishes, though it be tried with fire, might be found to praise and honor and glory at the appearing of Jesus Christ:
Jer 23:29 Is not my word like as a fire? said the LORD; and like a hammer that breaks the rock in pieces?
Could this be the blood of the slayed angels in heaven? After the sword kills in heaven it decent to earth to slay Edomites.
The word "burned" is translated from the Greek word katakaio-
Exod 29:14 But the flesh of the bullock, and his skin, and his dung, shall you burn/seraph with fire without the camp: it is a sin offering.
Seraph is also closely related to the word 'sar' which mean prince. A prince is a servant or a king. So, all that combined makes it seem likely that Seraph angels are send for judgment. Not literal fire storms of burning coals. The verses give no information what it will really look like. There are all sort of speculations like atom bombs or meteor showers but that info simply can’t be proven from the 1st Trumpet verses.
A third of the earth
Earlier we saw that 'of the earth' is a reference to people that are in covenant with satan. So saints are not part of this third because they are in the light (rainbow) covenant.
The people of the earth are not those who are in their rooms, the one that listen to God. The beast out of the earth is a leader that comes from among 'the people from the earth'. The beast comes from among the sinners
A third of the trees
Trees are leaders.
All the green grass
One thing is clear if one third of the vegetation is destroyed it will cause major climate issues like sunlight being blocked by smoke. The reduction of farmland won’t do any good either. The Temple door has opened. Let’s join the morning service :)