Try this
$args = array(
'posts_per_page' => -1,
'post_type' => 'product',
'meta_key' => 'var_confirmed_date',
'meta_type' => 'DATE',
'orderby' => 'meta_value_date',
'order' => 'ASC',
'tax_query' => array(
array(
'taxonomy' => 'destination',
'field' => 'id',
'terms' => array($t_id)
)
),
'meta_query' => array(
array(
'key' => 'var_confirmed_date',
'value' => date("Y-m-d",time()),
'compare' => '>=',
'type' => 'DATE',
),
),
);
$loop = new WP_Query( $args );