Te anexo una macro, la probé con 40 mil y tarda 3 minutos
Sub QuitaFilas()
'Act Por Dante Amor
Dim u As Double, i As Double, j As Double
Dim r As Range, a
Dim h As Object
Application.ScreenUpdating = False
Application.StatusBar = False
Set h = Sheets("Base")
u = h.Range("V" & Rows.Count).End(xlUp).Row
a = Range("V1:V" & u)
'
For i = 1 To UBound(a)
If a(i, 1) <> "CLIMA" Then
Set r = h.Range("V" & i)
j = i
Exit For
End If
Next
For i = j To u
Application.StatusBar = "Leyendo registro " & i
If a(i, 1) <> "CLIMA" Then
Set r = Union(r, h.Range("V" & i))
End If
Next i
r.EntireRow.Delete
Set r = Nothing
Application.StatusBar = False
Application.ScreenUpdating = True
End Sub
Otra opción, es que filtres la hoja por "CLIMA" y los registros encontrados los copies a otra hoja.
Entonces en la otra hoja tendrás la base depurada.